Compositions for and method of treating acid-base disorders

Abstract

Pharmaceutical compositions for and methods of treating an animal, including a human, and methods of preparing such compositions. The pharmaceutical compositions contain nonabsorbable compositions and may be used, for example, to treat diseases or other metabolic conditions in which removal of protons, the conjugate base of a strong acid and / or a strong acid from the gastrointestinal tract would provide physiological benefits such as normalizing serum bicarbonate concentrations and the blood pH in an animal, including a human.

Description

COMPOSITIONS FOR AND METHOD OF TREATING ACID-BASE DISORDERS

[0001] The present invention generally relates to methods of treating acid- base disorders that may be used, for example, in the treatment of metabolic acidosis.

[0002] Metabolic acidosis is the result of metabolic and dietary processes that in various disease states create a condition in which non-volatile acids accumulate in the body, causing a net addition of protons (H+) or the loss of bicarbonate (HC03").Metabolic acidosis occurs when the body accumulates acid from metabolic and dietary processes and the excess acid is not completely removed from the body by the kidneys. Chronic kidney disease is often accompanied by metabolic acidosis due to the reduced capacity of the kidney to excrete hydrogen ions secondary to an inability to reclaim filtered bicarbonate (HCO3"), synthesize ammonia (ammoniagenesis), and excrete titratable acids. Clinical practice guidelines recommend initiation of alkali therapy in patients with non-dialysis-dependent chronic kidney disease (CKD) when the serum bicarbonate level is <22 mEq / L to prevent or treat complications of metabolic acidosis. (Clinical practice guidelines for nutrition in chronic renal failure, K / DOQI, NationalKidney Foundation, Am. J. Kidney Dis. 2000; 35:S1 -140; Raphael, KL, Zhang, Y, Wei, G, et al. 2013, Serum bicarbonate and mortality in adults in NHANES III, Nephrol. Dial. Transplant 28: 1207-1213). These complications include malnutrition and growth retardation in children, exacerbation of bone disease, increased muscle degradation, reduced albumin synthesis, and increased inflammation. (Leman, J, Litzow, JR,Lennon, EJ. 1966. The effects of chronic acid loads in normal man: further evidence for the participation of bone mineral in the defense against chronic metabolic acidosis, J. Clin. Invest. 45: 1608-1614; Franch HA, Mitch WE, 1998, Catabolism in uremia: the impact of metabolic acidosis, J. Am. Soc. Nephrol. 9: S78-81 ; Ballmer, PE, McNurlan, MA, Hulter, HN, et al., 1995, Chronic metabolic acidosis decreases albumin synthesis and induces negative nitrogen balance in humans, J. Clin. Invest. 95: 39-45; Farwell, WR, Taylor, EN, 2010, Serum anion gap, bicarbonate and biomarkers of inflammation in healthy individuals in a national survey, CMAJ 182: 137-141 ). Overt metabolic acidosis is present in a large proportion of patients when the estimated glomerular filtration rate is below 30 ml / min / 1 .73m2. (KDOQI bone guidelines: American Journal of Kidney Diseases (2003) 42:S1 -S201 . (suppl); Widmer B, Gerhardt RE, Harrington JT, Cohen JJ, Serum electrolyte and acid base composition: The influence of graded degrees of chronic renal failure, Arch Intern Med139: 1099-1 102, 1979; Dobre M, Yang, W, Chen J,et. al., Association of serum bicarbonate with risk of renal and cardiovascular outcomes in CKD: a report from the chronic renal insufficiency cohort (CRIC) study. Am. J. Kidney Dis. 62: 670-678, 2013; Yaqoob, MM. Acidosis and progression of chronic kidney disease. Curr. Opin. Nephrol. Hypertens. 19: 489-492, 2010).

[0003] Metabolic acidosis, regardless of etiology, lowers extracellular fluid bicarbonate and, thus, decreases extracellular pH. The relationship between serum pH and serum bicarbonate is described by the Henderson-Hasselbalch equation pH = pK + log [HCO3"] / [(0.03X PaC02)] where 0.03 is the physical solubility coefficient for CO2, [HCO3"] and PaC02 are the concentrations of bicarbonate and the partial pressure of carbon dioxide, respectively.

[0004] There are several laboratory tests that can be used to define metabolic acidosis. The tests fundamentally measure either bicarbonate (HCO3") or proton (H+) concentration in various biological samples, including venous or arterial blood. These tests can measure either bicarbonate (HCO3") or proton (H+) concentration by enzymatic methodology, by ion selective electrodes or by blood gas analysis. In both the enzymatic and ion selective electrode methods, bicarbonate is "measured." Using blood gas analysis, bicarbonate level can be calculated using the Henderson-Hasselbalch equation.

[0005] Arterial blood gas (ABG) analysis is commonly performed for clinical evaluation, but the procedure has certain limitations in the form of reduced patient acceptability because of painful procedure and the potential to cause complications such as arterial injury, thrombosis with distal ischaemia, haemorrhage, aneurysm formation, median nerve damage and reflex sympathetic dystrophy. Venous blood gas (VBG) analysis is a relatively safer procedure as fewer punctures are required thus reducing the risk of needle stick injury to the health care workers. Therefore, as set out below, when the invention requires assessment of metabolic acidosis, it is preferred to complete this assessment using VBG analysis. Any measurements specified herein are preferably achieved by VBG analysis where possible, for example measurements of blood or serum bicarbonate levels.

[0006] The most useful measurements for the determination of acidosis rely on a measurement of the venous plasma bicarbonate (or total carbon dioxide [tC02]), or arterial plasma bicarbonate (or total carbon dioxide [tC02]), serum electrolytes CI", K+,and Na+, and a determination of the anion gap. In the clinical laboratory, measurement of venous plasma or serum electrolytes includes an estimation of the tC02. This measurement reflects the sum of circulating C02[i.e., the total C02represented by bicarbonate (HC03"), carbonic acid, (H2C03) and dissolved C02(0.03 X PC02)]. tC02can also be related to HCO3"by using a simplified and standardized form of theHenderson-Hasselbalch equation: tC02= HC03"+ 0.03 PC02, where PC02is the measured partial pressure of C02.Since HC03"concentration is greater than 90% of the tC02, and there are small amounts of H2C03, then venous tC02is often used as a reasonable approximation of the venous HCO3"concentration in the blood. Especially during chronic kidney disease, an abnormal plasma HCO3"value <22 mEq / L generally indicates metabolic acidosis.

[0007] Changes in serum CI"concentration can provide additional insights into possible acid-base disorders, particularly when they are disproportionate to changes in serum Na+concentration. When this occurs, the changes in serum CI"concentration are typically associated with reciprocal changes in serum bicarbonate. Thus, in metabolic acidosis with normal anion gap, serum CI"increases >105 mEq / L as serum bicarbonate decreases <22 mEq / L.

[0008] Calculation of the anion gap [defined as the serum Na+- (CI"+ HCO3")] is an important aspect of the diagnosis of metabolic acidosis. Metabolic acidosis may be present with a normal or an elevated anion gap. However, an elevated anion gap commonly signifies the presence of metabolic acidosis, regardless of the change in serum HCO3". An anion gap greater than 20 mEq / L (normal anion gap is 8 to 12 mEq / L) is a typical feature of metabolic acidosis.

[0009] Arterial blood gases are used to identify the type of an acid-base disorder and to determine if there are mixed disturbances. In general, the result of arterial blood gas measures should be coordinated with history, physical exam and the routine laboratory data listed above. An arterial blood gas measures the arterial carbon dioxide tension (PaC02), acidity (pH), and the oxygen tension (Pa02). The HCO3"concentration is calculated from the pH and the PaC02. Hallmarks of metabolic acidosis are a pH <7.35, PaC02<35 mm Hg and HC03"<22 mEq / L. The value of Pa02(normal 80-95 mmHg) is not used in making the diagnosis of metabolic acidosis but may be helpful in determining the cause. Acid-base disturbance are first classified as respiratory or metabolic. Respiratory disturbances are those caused by abnormalpulmonary elimination of CO2, producing an excess (acidosis) or deficit (alkalosis) of CO2 (carbon dioxide) in the extracellular fluid. In respiratory acid-base disorders, changes in serum bicarbonate (HC03") are initially a direct consequence of the change in PCO2 with a greater increase in PCO2 resulting in an increase in HCO3". (Adrogue HJ, Madias NE, 2003, Respiratory acidosis, respiratory alkalosis, and mixed disorders, in Johnson RJ, Feehally J (eds): Comprehensive Clinical Nephrology. London, CV Mosby, pp. 167-182). Metabolic disturbances are those caused by excessive intake of, or metabolic production or losses of, nonvolatile acids or bases in the extracellular fluid. These changes are reflected by changes in the concentration of bicarbonate anion (HCO3") in the blood; adaptation in this case involves both buffering (immediate), respiratory (hours to days) and renal (days) mechanisms. (DuBose TD, MacDonald GA: renal tubular acidosis, 2002, in DuBose TD, Hamm LL (eds): Acid-base and electrolyte disorders: A companion to Brenners and Rector's the Kidney, Philadelphia, WB Saunders, pp. 189-206).

[0010] The overall hydrogen ion concentration in the blood is defined by the ratio of two quantities, the serum HCO3"content (regulated by the kidneys) and the PCO2 content (regulated by the lungs) and is expressed as follows:[H+] oc (PC02 / [HC03"])

[0011] The consequence of an increase in the overall hydrogen ionconcentration is a decline in the major extracellular buffer, bicarbonate. Normal blood pH is between 7.38 and 7.42, corresponding to a hydrogen ion (H+) concentration of 42 to 38 nmol / L (Goldberg M: Approach to Acid-Base Disorders. 2005. In Greenberg A, Cheung AK (eds) Primer on Kidney Diseases, National Kidney Foundation,Philadelphia, Elsevier-Saunders, pp. 104-109.). Bicarbonate (HC03") is an anion that acts to buffer against pH disturbances in the body, and normal levels of plasma bicarbonate range from 22-26 mEq / L (Szerlip HM: Metabolic Acidosis, 2005, inGreenberg A, Cheung AK (eds) Primer on Kidney Diseases, National KidneyFoundation, Philadelphia, Elsevier-Saunders, pp. 74-89.). Acidosis is the process which causes a reduction in blood pH (acidemia) and reflects the accumulation of hydrogen ion (H+) and its consequent buffering by bicarbonate ion (HCO3") resulting in a decrease in serum bicarbonate. Metabolic acidosis can be represented as follows:2 C02+ 2 H20 ^ H2C03+ HC03"+ H ·+A low high(Clinical practice guidelines for nutrition in chronic renal failure. K / DOQI, National Kidney Foundation. Am. J. Kidney Dis. 2000; 35:S1 -140). Using this balance equation, the loss of one HCO3"is equivalent to the addition of one H+and conversely, the gain of one HCO3"is equivalent to the loss of one H+. Thus, changes in blood pH, particularly increases in H+(lower pH, acidosis) can be corrected by increasing serum HCO3"or, equivalently, by decreasing serum H+.

[0012] In order to maintain extracellular pH within the normal range, the daily production of acid must be excreted from the body. Acid production in the body results from the metabolism of dietary carbohydrates, fats and amino acids. Complete oxidation of these metabolic substrates produces water and CO2. The carbon dioxide generated by this oxidation (~20,000 mmol / day) is efficiently exhaled by the lungs, and represents the volatile acid component of acid-base balance.In contrast, nonvolatile acids (~50-100 mEq / day) are produced by the metabolism of sulfate- and phosphate-containing amino acids and nucleic acids.Additional nonvolatile acids (lactic acid, butyric acid, acetic acid, other organic acids) arise from the incomplete oxidation of fats and carbohydrates, and from carbohydrate metabolism in the colon, where bacteria residing in the colon lumen convert the substrates into small organic acids that are then absorbed into the bloodstream. The impact of short chain fatty acids on acidosis is somewhat minimized by anabolism, for example into long-chain fatty acids, or catabolism to water and C02.

[0014] The kidneys maintain pH balance in the blood through twomechanisms: reclaiming filtered HCO3"to prevent overall bicarbonate depletion and the elimination of nonvolatile acids in the urine. Both mechanisms are necessary to prevent bicarbonate depletion and acidosis.

[0015] In the first mechanism, the kidneys reclaim HCO3"that is filtered by the glomerulus. This reclamation occurs in the proximal tubule and accounts for ~4500 mEq / day of reclaimed HCO3". This mechanism prevents HCO3"from being lost in the urine, thus preventing metabolic acidosis. In the second mechanism, the kidneyseliminate enough H+to equal the daily nonvolatile acid production through metabolism and oxidation of protein, fats and carbohydrates. Elimination of this acid load is accomplished by two distinct routes in the kidney, comprising active secretion of H+ion and ammoniagenesis. The net result of these two interconnected processes is the elimination of the 50-100 mEq / day of nonvolatile acid generated by normal metabolism.

[0016] Thus, normal renal function is needed to maintain acid-base balance. During chronic kidney disease, filtration and reclamation of HCO3"is impaired as is generation and secretion of ammonia. These deficits rapidly lead to chronic metabolic acidosis which is, itself, a potent antecedent to end-stage renal disease. With continued acid production from metabolism, a reduction in acid elimination will disturb theH+ / HCO3"balance such that blood pH falls below the normal value of pH = 7.38 -7.42.

[0017] Treatment of metabolic acidosis by alkali therapy is usually indicated to raise and maintain the plasma pH to greater than 7.20. Sodium bicarbonate (NaHCOs) is the agent most commonly used to correct metabolic acidosis. NaHCO3can be administered intravenously to raise the serum HCO3"level adequately to increase the pH to greater than 7.20. Further correction depends on the individual situation and may not be indicated if the underlying process is treatable or the patient is asymptomatic. This is especially true in certain forms of metabolic acidosis. For example, in high-anion gap (AG) acidosis secondary to accumulation of organic acids, lactic acid, and ketones, the cognate anions are eventually metabolized to HCO3". When the underlying disorder is treated, the serum pH corrects; thus, caution should be exercised in these patients when providing alkali to raise the pH much higher than 7.20, to prevent an increase in bicarbonate above the normal range (> 26 mEq / L).

[0018] Citrate is an appropriate alkali therapy to be given orally or IV, either as the potassium or sodium salt, as it is metabolized by the liver and results in the formation of three moles of bicarbonate for each mole of citrate. Potassium citrate administered IV should be used cautiously in the presence of renal impairment and closely monitored to avoid hyperkalemia.

[0019] Intravenous sodium bicarbonate (NaHCOs) solution can beadministered if the metabolic acidosis is severe or if correction is unlikely to occur without exogenous alkali administration. Oral alkali administration is the preferred route of therapy in persons with chronic metabolic acidosis. The most common alkali formsfor oral therapy include NaHC03tablets where 1 g of NaHC03is equal to 1 1 .9 mEq of HCO3". However, the oral form of NaHC03is not approved for medical use and the package insert of the intravenous sodium bicarbonate solution includes the following contraindications, warnings and precautions (Hospira label for NDC 0409-3486-16):Contraindications: Sodium Bicarbonate Injection, USP is contraindicated in patients who are losing chloride by vomiting or from continuousgastrointestinal suction, and in patients receiving diuretics known toproduce a hypochloremic alkalosis.Warnings: Solutions containing sodium ions should be used with great care, if at all, in patients with congestive heart failure, severe renalinsufficiency and in clinical states in which there exists edema with sodium retention. In patients with diminished renal function, administration ofsolutions containing sodium ions may result in sodium retention. Theintravenous administration of these solutions can cause fluid and / or solute overloading resulting in dilution of serum electrolyte concentrations,overhydration, congested states or pulmonary edema.Precautions: [... ] The potentially large loads of sodium given withbicarbonate require that caution be exercise in the use of sodiumbicarbonate in patients with congestive heart failure or other edematous or sodium-retaining states, as well as in patients with oliguria or anuria.

[0020] Acid-base disorders are common in chronic kidney disease and heart failure patients. Chronic kidney disease (CKD) progressively impairs renal excretion of the approximately 1 mmol / kg body weight of hydrogen ions generated in healthy adults (Yaqoob, MM. 2010, Acidosis and progression of chronic kidney disease, Curr. Opin. Nephrol. Hyperten. 19:489-492.). Metabolic acidosis, resulting from the accumulation of acid (H+) or depletion of base (HCO3") in the body, is a common complication of patients with CKD, particularly when the glomerular filtration rate (GFR, a measure of renal function) falls below 30 ml / min / 1 .73m2. Metabolic acidosis has profound long term effects on protein and muscle metabolism, bone turnover and the development of renal osteodystrophy. In addition, metabolic acidosis influences a variety of paracrine and endocrine functions, again with long term consequences such as increasedinflammatory mediators, reduced leptin, insulin resistance, and increased corticosteroid and parathyroid hormone production (Mitch WE, 1997, Influence of metabolic acidosison nutrition, Am. J. Kidney Dis. 29:46-48.). The net effect of sustained metabolic acidosis in the CKD patient is loss of bone and muscle mass, a negative nitrogen balance, and the acceleration of chronic renal failure due to hormonal and cellular abnormalities (De Brito-Ashurst I, Varagunam M, Raftery MJ, et al, 2009, Bicarbonate supplementation slows progression of CKD and improves nutritional status, J. Am. Soc. Nephrol. 20: 2075-2084). Conversely, the potential concerns with alkali therapy in CKD patients include expansion of extracellular fluid volume associated with sodium ingestion, resulting in the development or aggravation of hypertension, facilitation of vascular calcification, and the decompensation of existing heart failure. CKD patients of moderate degree (GFR at 20-25% of normal) first develop hyperchloremic acidosis with a normal anion gap due to the inability to reclaim filtered bicarbonate and excrete proton and ammonium cations. As they progress toward the advanced stages of CKD the anion gap increases, reflective of the continuing degradation of the kidney's ability to excrete the anions that were associated with the unexcreted protons. Serumbicarbonate in these patients rarely goes below 15 mmol / L with a maximum elevated anion gap of approximately 20 mmol / L. The non-metabolizable anions that accumulate in CKD are buffered by alkaline salts from bone (Lemann J Jr, Bushinsky DA, Hamm LL Bone buffering of acid and base in humans. Am. J. Physiol Renal Physiol. 2003 Nov, 285(5): F81 1 -32).

[0021] The majority of patients with chronic kidney disease have underlying diabetes (diabetic nephropathy) and hypertension, leading to deterioration of renal function. In almost all patients with hypertension a high sodium intake will worsen the hypertension. Accordingly, kidney, heart failure, diabetes and hypertensive guidelines strictly limit sodium intake in these patients to less than 1 .5 g or 65 mEq per day (HFSA 2010 guidelines, Lindenfeld 2010, J Cardiac Failure V16 No 6 P475). Chronic antihypertensive therapies often induce sodium excretion (diuretics) or modify the kidney's ability to excrete sodium and water (such as, for example, Renin AngiotensinAldosterone System inhibiting "RAASi" drugs). However, as kidney functiondeteriorates, diuretics become less effective due to an inability of the tubule to respond. The RAASi drugs induce life-threatening hyperkalemia as they inhibit renal potassium excretion. Given the additional sodium load, chronically treating metabolic acidosis patients with amounts of sodium-containing base that often exceed the total daily recommended sodium intake is not a reasonable practice. As a consequence, oralsodium bicarbonate is not commonly prescribed chronically in these diabetic nephropathy patients. Potassium bicarbonate is also not acceptable as patients with CKD are unable to readily excrete potassium, leading to severe hyperkalemia.

[0022] Despite these shortcomings, the role of oral sodium bicarbonate has been studied in the small subpopulation of non-hypertensive CKD patients. As part of the Kidney Research National Dialogue, alkali therapy was identified as having the potential to slow the progression of CKD, as well as to correct metabolic acidosis. The annual age-related decline in glomerular filtration rate (GFR) after the age of 40 is 0.75- 1.0 ml / min / 1 .73m2in normal individuals. In CKD patients with fast progression, a steeper decline of >4 ml / min / 1 .73m2annually can be seen. Glomerular filtration rate or estimated glomerular filtration rate is typically used to characterize kidney function and the stage of chronic kidney disease. The five stages of chronic kidney disease and the GFR for each stage is as follows:Stage 1 with normal or high GFR (GFR > 90 mL / min / 1 .73 m2) Stage 2 Mild CKD (GFR = 60-89 mL / min / 1 .73 m2)Stage 3A Moderate CKD (GFR = 45-59 mL / min / 1 .73 m2)Stage 3B Moderate CKD (GFR = 30-44 mL / min / 1 .73 m2)Stage 4 Severe CKD (GFR = 15-29 mL / min / 1.73 m2)Stage 5 End Stage CKD (GFR <15 mL / min / 1.73 m2).

[0023] In one outcome study, De Brito-Ashurst et al showed that bicarbonate supplementation preserves renal function in CKD (De Brito-Ashurst I, Varagunam M, Raftery MJ, et al, 2009, Bicarbonate supplementation slows progression of CKD and improves nutritional status, J. Am. Soc. Nephrol. 20: 2075-2084). The study randomly assigned 134 adult patients with CKD (creatinine clearance [CrCI] 15 to 30 ml / min per 1.73 m2) and serum bicarbonate 16 to 20 mmol / L to either supplementation with oral sodium bicarbonate or standard of care for 2 years. The average dose of bicarbonate in this study was 1 .82 g / day, which provides 22 mEq of bicarbonate per day. The primary end points were rate of CrCI decline, the proportion of patients with rapid decline of CrCI (>3ml / min per 1 .73 m2 / yr), and end-stage renal disease ("ESRD") (CrCI <10 ml / min). Compared with the control group, decline in CrCI was slower with bicarbonatesupplementation (decrease of 1 .88 ml / min per 1.73 m2for patients receivingbicarbonate versus a decrease of 5.93 ml / min per 1 .73 m2for control group; P<0.0001 ). Patients supplemented with bicarbonate were significantly less likely to experience rapid progression (9% versus 45%; relative risk 0.15; 95% confidence interval 0.06 to 0.40; P < 0.0001 ). Similarly, fewer patients supplemented with bicarbonate developed ESRD (6.5% versus 33%; relative risk 0.13; 95% confidence interval 0.04 to 0.40; P < 0.001 ).

[0024] Hyperphosphatemia is a common co-morbidity in patients with CKD, particularly in those with advanced or end-stage renal disease. Sevelamerhydrochloride is a commonly used ion-exchange resin that reduces serum phosphate concentration. However, reported drawbacks of this agent include metabolic acidosis apparently due to the net absorption of HCI in the process of binding phosphate in the small intestine. Several studies in patients with CKD and hyperphosphatemia who received hemodialysis or peritoneal dialysis found decreases in serum bicarbonate concentrations with the use of sevelamer hydrochloride (Brezina, 2004 Kidney Int. V66 S90 (2004) S39-S45; Fan, 2009 Nephrol Dial Transplant (2009) 24:3794).

[0025] Among the various aspects of the present disclosure, the following is a useful guide for one method for treating metabolic acidosis (without wishing to be bound by theory). When an H+is pumped into the stomach a HCO3"enters the systemic circulation and raises the serum bicarbonate concentration. The initial binding of gastric H+to a nonabsorbable composition as described herein results in HC03"entering the systemic circulation and raising the serum bicarbonate concentration. The more H+bound the greater the increase in systemic HCO3". The binding of CI"thenonabsorbable composition prevents subsequent exchange of luminal CI"for HCO3"which would counteract the initial rise in HC03". The analogous clinical situation to administering the composition is vomiting. Administration of the composition is essentially causing the loss of gastric HCI as in vomiting. If a person vomits they lose gastric HCI and have an increase in serum bicarbonate. The increase in serum bicarbonate persists only if they are not given a lot of oral CI", for example as NaCI, which would allow subsequent exchange of intestinal CI"for HCO3"and dissipate the increase in serum bicarbonate concentration. The disclosure is not limited by these requirements, and instead they are set out in full below.

[0026] Among the various aspects of the present disclosure may be noted a method of treating an individual afflicted with a chronic acid / base disorder characterized by a baseline serum bicarbonate value of less than 22 mEq / l. The method comprisesoral administration of a pharmaceutical composition comprising a nonabsorbable composition having the capacity to bind a target species selected from the group consisting of protons, a conjugate base of a strong acid, and a strong acid as it transits the digestive system.

[0027] Another aspect of the present disclosure is a method of treating an individual afflicted with an acid-base disorder characterized by a baseline serum bicarbonate value of less than 22 mEq / l, the method comprising oral administration of a daily dose of a pharmaceutical composition having the capacity to remove at least 5 meq of a target species as it transits the digestive system to achieve a clinically significant increase in the serum bicarbonate value of at least 1 mEq / l from baseline within a treatment period not greater than 1 month. The target species is selected from the group consisting of protons, strong acids, and conjugate bases of strong acids.

[0028] Another aspect of the present disclosure is a composition for use in a method of treating metabolic acidosis in an adult human patient wherein in said treatment 0.1 - 12 g of said composition is administered to the patient per day, said composition being a nonabsorbable composition having the capacity to remove protons from the patient, wherein the nonabsorbable composition is characterized by a chloride ion binding capacity of at least 2.5 mEq / g in a Simulated Small Intestine Inorganic Buffer ("SIB") assay. In this aspect, the composition may be administered orally, and so would be an orally administered nonabsorbable composition as defined herein.

[0029] Another aspect of the present disclosure is a composition for use in a method of treating metabolic acidosis in an adult human patient by increasing that patient's serum bicarbonate value by at least 1 mEq / L over 15 days of treatment (i.e., within 15 days of treatment), said composition being a nonabsorbable composition having the capacity to remove protons from the patient. In this aspect, the composition may be administered orally, and so would be an orally administered nonabsorbable composition as defined herein.

[0030] Another aspect of the present disclosure is a composition for use in a method of treating metabolic acidosis in an adult human patient, said patient having a serum bicarbonate level of less than 20 mEq / L prior to treatment, said composition being a nonabsorbable composition having the capacity to remove protons from thepatient. In this aspect, the composition may be administered orally, and so would be an orally administered nonabsorbable composition as defined herein.

[0031] Another aspect of the present disclosure is a composition for use in a method of treating metabolic acidosis in an adult human patient by increasing that patient's serum bicarbonate value by at least 1 mEq / L over 15 days of treatment, wherein in said treatment >12 - 100g of said polymer is administered to the patient per day, said composition being a nonabsorbable composition having the capacity to remove protons from the patient, wherein the nonabsorbable composition ischaracterized by a chloride ion binding capacity of at least 2.5 mEq / g in a Simulated Small Intestine Inorganic Buffer ("SIB") assay. In this aspect, the composition may be administered orally, and so would be an orally administered nonabsorbable composition as defined herein.

[0032] Another aspect of the present disclosure is a composition for use in a method of treating metabolic acidosis in an adult human patient wherein in said treatment >12 - 100g of said composition is administered to the patient per day, said composition being a nonabsorbable composition having the capacity to remove protons from the patient, wherein the nonabsorbable composition is characterized by a chloride ion binding capacity of less than 2.5 mEq / g in a Simulated Small Intestine Inorganic Buffer ("SIB") assay. In this aspect, the composition may be administered orally, and so would be an orally administered nonabsorbable composition as defined herein.

[0033] In certain embodiments, the orally administered nonabsorbable composition comprises cations (such as Na+, K+, Mg2+, Ca2+Li+, or a combination thereof) that are exchanged for protons as the nonabsorbable composition transits the digestive system, and the protons are then excreted from the body along with the nonabsorbable composition upon defecation. The net effect is reduction in protons in the body, in exchange for an increase in one or more cations. In this embodiment, the pharmaceutical composition may also optionally comprise a pharmaceutically acceptable carrier, diluent or excipient, or a combination thereof that does not significantly interfere with the proton-binding characteristics of the nonabsorbable composition in vivo. Optionally, the pharmaceutical composition may also comprise an additional therapeutic agent.

[0034] In certain embodiments, the orally administered nonabsorbable composition comprises anions that are exchanged for chloride ions and if the anion comprised by the orally administered nonabsorbable composition is a stronger base (e.g., OH") than the removed base (e.g. , CI", HSO4", or SO42"), the net effect is the removal of a strong acid from the body (e.g. , HCI or H2SO4) in exchange for a weak acid (e.g., H2O). In this embodiment, the pharmaceutical composition may also optionally comprise a pharmaceutically acceptable carrier, diluent or excipient, or a combination thereof that does not significantly interfere with the chloride-binding characteristics of the nonabsorbable composition in vivo. Optionally, the pharmaceutical composition may also comprise an additional therapeutic agent.

[0035] In certain embodiments, the orally administered nonabsorbable composition is a neutral composition having the capacity to bind and remove a strong acid, such as HCI or H2SO4, from the body upon oral administration. Thenonabsorbable composition may, but does not necessarily, introduce (i.e., by ion exchange) counterbalancing cations or anions in the process of removing the acid. In this embodiment, binding of both ionic species of HCI (H+and CI") may be achieved through favorable surface energy of the bulk material, which can include hydrogen bonding and other interactions as well as ionic interactions. Complexation of HCI can occur on functional groups that are dehydrated and upon administration in an acidic aqueous medium, result in the hydrochloride salt of the functional group.

[0036] Among the various aspects of the present disclosure may further be noted a method of treating an individual afflicted with a chronic acid / base disorder comprising oral administration of a pharmaceutical composition containing anonabsorbable composition having the capacity to bind protons and chloride ions as it transits the digestive system and remove the bound protons and chloride ions from the individual's digestive system via defecation. In each of these embodiments, the pharmaceutical composition may also optionally comprise a pharmaceutically acceptable carrier, diluent or excipient, or a combination thereof that does not significantly interfere with the chloride-binding characteristics of the nonabsorbable composition in vivo. Optionally, the pharmaceutical composition may also comprise an additional therapeutic agent.

[0037] In one embodiment, any of the methods of treating an individual afflicted with an acid-base disorder disclosed in this application comprise: i) theindividual having a diet regimen, or ii) the method including, specifying, prescribing or recommending a diet regimen. In one embodiment, said diet regimen is an alkaline diet regimen. In one embodiment, said diet regimen is a conventional low-protein diet regimen (< 0.6 g / kg per day). In one embodiment, said diet regimen is a very low- protein diet regimen (0.3-0.4 g / kg per day). In one embodiment, said diet regimen is a vegetarian diet regimen. In one embodiment, said said diet regimen is a vegetarian diet regimen supplemented with either essential amino acids or a mixture of essential amino acids and nitrogen-free ketoanalogues (keto diet regimen). In one embodiment, said diet regimen is ketoanalogue-supplemented vegetarian very low-protein diet. In one embodiment, said diet regimen is a vegan diet regimen. In one embodiment, said diet regimen is a casein diet regimen. In one embodiment, said diet regimen is an adenine- containing diet regimen. In one embodiment, said diet regimen comprises one or more base-producing vegetables (e.g. carrots, cauliflower, eggplant, lettuce, potatoes, spinach, tomatoes, or zucchini, or a combination thereof). In one embodiment, said diet regimen comprises one or more base-producing fruits (e.g. apple, apricot, oranges, peaches, pears, raisins, or strawberries, or a combination thereof). In one embodiment, said diet regimen does not comprise acid-producing meat.

[0038] In one embodiment the diet comenses one year before administering the nonabsorbable composition. In another embodiment the diet comenses six months before administering the nonabsorbable composition. In another embodiment the diet comenses one month before administering the nonabsorbable composition. In another embodiment the diet regimen comenses when the administering of the nonabsorbable composition comenses. In another embodiment the diet comenses one month after administering the nonabsorbable composition. In another embodiment the diet comenses six months after administering the nonabsorbable composition. In another embodiment the diet comenses one year after administering the nonabsorbable composition.

[0039] De Brito-Ashurst et al. is one of six published prospective randomized, controlled clinical studies of alkali supplementation and dietary intervention, which demonstrate that increasing serum bicarbonate levels results in improved renal outcomes associated with chronic metabolic acidosis. The five other studies are:Garneata L, Stancu A, Dragomir D, et al., 2016, Ketoanalogue-SupplementedVegetarian Very Low-Protein Diet and CKD Progression, J. Am. Soc. Nephrol. 27:2164-2176; Phisitkul S, Khanna A, Simoni J, et al., 2010, Amelioration of metabolic acidosis in patients with low GFR reduced kidney endothelin production and kidney injury, and better preserved GFR, Kidney International 77: 617-623; Goraya N, Simoni J, Jo C, Wesson D, 2013, A comparison of treating metabolic acidosis in CKD stage 4 hypertensive kidney disease with fruits and vegetables or sodium bicarbonate, Clin. J. Am. Soc. Nephrol. 8: 371 -381 ; Goraya N, Simoni J, Jo C, Wesson D, 2014, Treatment of metabolic acidosis in patients with stage 3 chronic kidney disease with fruits and vegetables or oral bicarbonate reduces urine angiotensinogen and preservesglomerular filtration rate, Kidney International 86: 1031 -1038; and Mahajan A, Simoni J, Sheather S, et al., 2010, Daily oral sodium bicarbonate preserves glomerular filtration rate by slowing its decline in early hypertensive nephropathy, Kidney International 78: 303-309.

[0040] Garneata et al. assessed the effects of a ketoanalogue-supplemented vegetarian very low protein diet (0.3 g / kg / day) in diet-compliant patients to those of a usual mixed-source low protein diet (0.6 g / kg / day). Baseline serum bicarbonate was similar in the two treatment groups (16.7-16.8 mEq / L), however the end of study serum bicarbonate value was significantly higher in the vegetarian very low protein diet group than the usual mixed-source low protein diet group. Efficacy of the vegetarian very low protein diet to reduce incidence of renal events was most noted in patients with initial eGFR <20 ml_ / min.1 .73m2.

[0041] In those embodiments in which the the nonabsorbable composition binds chloride ions, it is generally preferred that the nonabsorbable composition selectively bind chloride ions relative to other physiologically significant competing anions such as bicarbonate equivalent anions, phosphate anions, and the conjugate bases of bile and fatty acids that are present in the Gl tract. Stated differently, it is generally preferred that the nonabsorbable composition remove more chloride ions than any other competing anion in the Gl tract.

[0042] In those embodiments in which the nonabsorbable composition binds protons, it is generally preferred that the nonabsorbable composition bind protons without delivering sodium, potassium, calcium, magnesium, and / or other electrolytes in exchange for the protons in an amount that is physiologically detrimental. As a result, treatment with the nonabsorbable composition will not significantly contribute to edema, hypertension, hyperkalemia, hypercalcemia or a similar disorder associated with anelevated load of sodium, potassium, calcium or other electrolyte. Similarly, in those embodiments in which the nonabsorbable composition binds protons, it is generally preferred that the nonabsorbable composition bind protons without removing an amount of sodium, potassium, calcium, magnesium and / or other electrolytes along with the protons. As a result, treatment with the nonabsorbable composition will not significantly contribute to hypotension, hypokalemia, hypocalcemia or other disorder associated with a depressed serum concentration of sodium, potassium, calcium, magnesium or other electrolyte.

[0043] In certain embodiments, the polymers preferably bind and maintain their ability to bind proton and anions at the physiological conditions found along the gastrointestinal (Gl) lumen. These conditions can change according to dietary intake (see, for example, Fordtran J, Locklear T. Ionic constituents and osmolality of gastric and small-intestinal fluids after eating. Digest Dis Sci. 1966; 1 1 (7):503-21 ) and location along the Gl tract (Binder, H et al. Chapters 41 -45 in "Medical Physiology", 2nd Edition, Elsevier

[2011] . Boron and Boulpaep [Ed.]). Rapid binding of proton and chloride in the stomach and small intestine is desirable. High binding levels and selectivity for chloride later in the Gl tract (lower small intestine and large intestine) is also desirable. In general, the polymers also preferably have a pKasuch that the majority of amines are protonated under the various pH and electrolyte conditions encountered along the Gl tract and are thereby capable of removing proton, along with an appropriate counter anion (preferably chloride), from the body into the feces.

[0044] Since the stomach is an abundant source of HCI, and the stomach is the first site of potential HCI binding (after the mouth), and since residence time in the stomach is short (gastric residence half-life of approximately 90 minutes), compared to the rest of the Gl tract (small intestine transit time of approximately 4 hours; whole gut transit time of 2-3 days; Read, NW et al. Gastroenterology

[1980] 79: 1276), it is desirable for the polymer of the present disclosure to demonstrate rapid kinetics of proton and chloride binding in the lumen of this organ, as well as in in vitro conditions designed to mimic the stomach lumen (e.g. SGF). Phosphate is a potential interfering anion for chloride binding in the stomach and small intestine, where phosphate is mostly absorbed (Cross, HS et al Miner Electrolyte Metab

[1990] 16: 1 15-24). Therefore rapid and preferential binding of chloride over phosphate is desirable in the small intestine and in in vitro conditions designed to mimic the small intestine lumen (e.g. SIB). Sincethe transit time of the colon is slow (2-3 days) relative to the small intestine, and since conditions in the colon will not be encountered by an orally administered polymer until after stomach and small intestine conditions have been encountered, kinetics of chloride binding by a polymer of the present disclosure do not have to be as rapid in the colon or in in vitro conditions designed to mimic the late small intestine / colon. It is, however, important that chloride binding and selectivity over other interfering anions is high, for example, at 24 and / or 48 hours or longer.

[0045] Other aspects and features will be in part apparent and in part pointed out hereinafter.BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Fig. 1A-1 C is a flow chart schematically depicting the mechanism of action of the polymer when passing through the gastrointestinal tract of an individual from oral ingestion / stomach (Fig. 1 A), to the upper Gl tract (FIG. 1 B) to the lower Gl tract / colon (Fig. 1 C).

[0047] Fig. 2 is a graph of the effect of TRC101 on serum bicarbonate in a rat model of adenine-induced nephropathy and metabolic acidosis in Part 1 of the study described in Example 1 .

[0048] Figs. 3A, 3B and 3C are graphs of the effect of TRC101 on fecal excretion of chloride (Fig. 3A), sulfate (Fig. 3B), and phosphate (Fig. 3C) in a rat model of adenine-induced nephropathy and metabolic acidosis in Part 1 of the study described in Example 1 .

[0049] Fig. 4 is a graph of the effect of TRC101 on serum bicarbonate in a rat model of adenine-induced nephropathy and metabolic acidosis in Part 2 of the study described in Example 1 .

[0050] Figs. 5A, 5B and 5C are graphs of the effect of TRC101 on fecal excretion of chloride (Fig. 5A), sulfate (Fig. 5B), and phosphate (Fig. 5C) in a rat model of adenine-induced nephropathy and metabolic acidosis in Part 2 of the study described in Example 1 .

[0051] Figs. 6A, 6B and 6C are graphs of the in vivo chloride (Fig. 6A), sulfate (Fig. 6B) and phosphate (Fig. 6C) binding capacities of test compound and bixalomer in a pig with normal renal function in the study described in Example 2.

[0052] Fig. 7 is a line graph showing the mean change in serum bicarbonate (SBC) from baseline (BL) and standard error (SE) by treatment group over time in a human study as described more fully in Example 3 (Part 1 ).

[0053] Fig. 8 is a bar graph showing the least squares mean (LS Mean) change from baseline (CFB) to end of treatment in serum bicarbonate (SBC) by treatment group in a human study as described more fully in Example 3 (Part 1 ). Single asterisk ("*") indicates statistically significant difference (p<0.5) and double asterisk ("**") indicates highly statistically significant difference (p<0.0001 ).

[0054] Fig. 9 is a bar graph showing the effect on serum bicarbonate (SBC) levels and standard error (SE) at days 8 and 15 resulting from treatment (Tx = treatment) and upon withdrawal of TRC101 in a human study as described more fully in Example 3 (Part 1 ).

[0055] Fig. 10 is a line graph showing the mean change in serum bicarbonate (SBC) and standard error (SE) for the four TRC101 active arms and the two placebo arms (pooled) of the study described more fully in Example 3 (Parts 1 and 2).

[0056] Fig. 1 1 is a bar graph showing the least squares mean (LS Mean) change from baseline (CFB) in serum bicarbonate (SBC) by treatment group over time for the four TRC101 active arms and the two placebo arms (pooled) of the study described more fully in Example 3 (Parts 1 and 2). Single asterisk ("*") indicates statistically significant difference (p<0.5) and double asterisk ("**") indicates highly statistically significant difference (p<0.0001 ).

[0057] Fig. 12 is a bar graph showing the treatment effect on serumbicarbonate (SBC) levels and standard error (SE) at days 8 and 15 resulting from treatment (Tx = treatment) with and upon withdrawal of TRC101 in a human study as described more fully in Example 3 (Parts 1 and 2).

[0058] Figs. 13A, 13B, 13C and 13D are graphs showing the changes in serum bicarbonate (Fig. 13A), serum chloride (Fig. 13B), serum sodium (Fig. 13C) and serum potassium (Fig. 13D) for the four TRC101 active arms (combined) vs the twoplacebo arms (pooled) over time for the study described more fully in Example 3 (Parts 1 and 2).

[0059] Fig. 14 is a graph showing the changes in the calculated anion gap for the four TRC101 active arms (combined) vs the two placebo arms (pooled) over time for the study described more fully in Example 3 (Parts 1 and 2).ABBREVIATIONS AND DEFINITIONS

[0060] The following definitions and methods are provided to better define the present invention and to guide those of ordinary skill in the art in the practice of the present invention. Unless otherwise noted, terms are to be understood according to conventional usage by those of ordinary skill in the relevant art.

[0061] The term "absorption capacity" as used herein in connection with a polymer and a swelling agent (or in the case of a mixture of swelling agents, the mixture of swelling agents) is the amount of the swelling agent (or such mixture) absorbed during a period of at least 16 hours at room temperature by a given amount of a dry polymer (e.g., in the form of a dry bead) immersed in an excess amount of the swelling agent (or such mixture).

[0062] The term "acrylamide" denotes a moiety having the structural formula H2C=CH-C(0)NR-*, where*denotes the point of attachment of the moiety to the remainder of the molecule and R is hydrogen, hydrocarbyl, or substituted hydrocarbyl.

[0063] The term "acrylic" denotes a moiety having the structural formula H2C=CH-C(0)0-*, where*denotes the point of attachment of the moiety to the remainder of the molecule.

[0064] The term "adult" refers to an individual over 18 years of age.

[0065] The term "alicyclic", "alicyclo" or "alicyclyl" means a saturated monocyclic group of 3 to 8 carbon atoms and includes cyclopentyl, cyclohexyl, cycloheptyl, and the like.

[0066] The term "aliphatic" denotes saturated and non-aromatic unsaturated hydrocarbyl moieties having, for example, one to about twenty carbon atoms or, in specific embodiments, one to about twelve carbon atoms, one to about ten carbonatoms, one to about eight carbon atoms, or even one to about four carbon atoms. The aliphatic groups include, for example, alkyl moieties such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, iso-amyl, hexyl and the like, and alkenyl moieties of comparable chain length.

[0067] The term "alkanol" denotes an alkyl moiety that has been substituted with at least one hydroxyl group. In some embodiments, alkanol groups are "lower alkanol" groups comprising one to six carbon atoms, one of which is attached to an oxygen atom. In other embodiments, lower alkanol groups comprise one to three carbon atoms.

[0068] The term "alkenyl group" encompasses linear or branched carbon radicals having at least one carbon-carbon double bond. The term "alkenyl group" can encompass conjugated and non-conjugated carbon-carbon double bonds orcombinations thereof. An alkenyl group, for example and without being limited thereto, can encompass two to about twenty carbon atoms or, in a particular embodiment, two to about twelve carbon atoms. In certain embodiments, alkenyl groups are "lower alkenyl" groups having two to about four carbon atoms. Examples of alkenyl groups include, but are not limited thereto, ethenyl, propenyl, allyl, vinyl, butenyl and 4-methylbutenyl. The terms "alkenyl group" and "lower alkenyl group", encompass groups having "cis" or "trans" orientations, or alternatively, "E" or "Z" orientations.

[0069] The term "alkyl group" as used, either alone or within other terms such as "haloalkyl group," "aminoalkyl group" and "alkylamino group", encompasses saturated linear or branched carbon radicals having, for example, one to about twenty carbon atoms or, in specific embodiments, one to about twelve carbon atoms. In other embodiments, alkyl groups are "lower alkyl" groups having one to about six carbon atoms. Examples of such groups include, but are not limited thereto, methyl, ethyl, n- propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, iso-amyl, hexyl and the like. In more specific embodiments, lower alkyl groups have one to four carbon atoms.

[0070] The term "alkylamino group" refers to amino groups directly attached to the remainder of the molecule via the nitrogen atom of the amino group and wherein the nitrogen atom of the alkylamino group is substituted by one or two alkyl groups. In some embodiments, alkylamino groups are "lower alkylamino" groups having one or two alkyl groups of one to six carbon atoms, attached to a nitrogen atom. In otherembodiments, lower alkylamino groups have one to three carbon atoms. Suitable "alkylamino" groups may be mono or dialkylamino such as N-methylamino, N- ethylamino, N,N-dimethylamino, Ν,Ν-diethylamino, pentamethyleneamine and the like.

[0071] The term "allyl" denotes a moiety having the structural formulaH2C=CH-CH2-*, where*denotes the point of attachment of the moiety to the remainder of the molecule and the point of attachment is to a heteroatom or an aromatic moiety.

[0072] The term "allylamine" denotes a moiety having the structural formula H2C=CH-CH2N(X8)(X9), wherein X8and X9are independently hydrogen, hydrocarbyl, or substituted hydrocarbyl, or X8and X9taken together form a substituted or unsubstituted alicyclic, aryl, or heterocyclic moiety, each as defined in connection with such term, typically having from 3 to 8 atoms in the ring.

[0073] The term "amine" or "amino" as used alone or as part of another group, represents a group of formula -N(X8)(X9), wherein X8and X9are independently hydrogen, hydrocarbyl, or substituted hydrocarbyl, heteroaryl, or heterocycio, or X8and X9taken together form a substituted or unsubstituted alicyclic, aryl, or heterocyclic moiety, each as defined in connection with such term, typically having from 3 to 8 atoms in the ring.

[0074] The term "aminoalkyl group" encompasses linear or branched alkyl groups having one to about ten carbon atoms, any one of which may be substituted with one or more amino groups, directly attached to the remainder of the molecule via an atom other than a nitrogen atom of the amine group(s). In some embodiments, the aminoalkyl groups are "lower aminoalkyl" groups having one to six carbon atoms and one or more amino groups. Examples of such groups include aminomethyl, aminoethyl, aminopropyl, aminobutyl and aminohexyl.

[0075] The terms "anion exchange material" and "cation exchange material" take their normal meaning in the art. For example, the terms "anion exchange material" and "cation exchange material" refer to materials that exchange anions and cations, respectively. Anion and cation exchange materials are typically water-insoluble substances which can exchange some of their cations or anions, respectively, for similarly charged anions or cations contained in a medium with which they are in contact. Anion exchange materials may contain positively charged groups, which are fixed to the backbone materials and allow passage of anions but reject cations. A non-exhaustive list of such positively charged groups includes: amino group, alkylsubstituted phosphine, and alkyl substituted sulphides. A non-exhaustive list of cation or anion exchange materials includes: clays (e.g., bentonite, kaolinite, and illite), vermiculite, zeolites (e.g., analcite, chabazite, sodalite, and clinoptilolite), synthetic zeolites, polybasic acid salts, hydrous oxides, metal ferrocyanides, and heteropolyacids. Cation exchange materials can contain negatively charged groups fixed to thebackbone material, which allow the passage of cations but reject anions. A non- exhaustive list of such negatively charged groups includes: sulphate, carboxylate, phosphate, and benzoate.

[0076] The term "aromatic group" or "aryl group" means an aromatic group having one or more rings wherein such rings may be attached together in a pendent manner or may be fused. In particular embodiments, an aromatic group is one, two or three rings. Monocyclic aromatic groups may contain 5 to 10 carbon atoms, typically 5 to 7 carbon atoms, and more typically 5 to 6 carbon atoms in the ring. Typical polycyclic aromatic groups have two or three rings. Polycyclic aromatic groups having two rings typically have 8 to 12 carbon atoms, preferably 8 to 10 carbon atoms in the rings.Examples of aromatic groups include, but are not limited to, phenyl, naphthyl, tetrahydronaphthyl, indanyl, biphenyl, phenanthryl, anthryl or acenaphthyl.

[0077] The term "bead" is used to describe a crosslinked polymer that is substantially spherical in shape.

[0078] The term "bicarbonate equivalent" is used to describe an organic acid or anion that yields bicarbonate when metabolized. Citrate and succinate areexemplary bicarbonate equivalents.

[0079] The term "binds" as used herein in connection with a polymer and one or more ions, that is, a cation (e.g. "proton-binding" polymer) and an anion, is an "ion- binding" polymer and / or when it associates with the ion, generally though notnecessarily in a non-covalent manner, with sufficient association strength that at least a portion of the ion remains bound under the in vitro or in vivo conditions in which the polymer is used for sufficient time to effect a removal of the ion from solution or from the body.

[0080] The term "ceramic material" takes its normal meaning in the art. In certain embodiments, the term "ceramic material" refers to an inorganic, nonmetallic,solid material comprising metal, nonmetal or metalloid atoms primarily held in ionic and covalent bonds. A non-exhaustive list of examples of ceramic materials includes:barium titanate, bismuth strontium calcium copper oxide, boron oxide, earthenware, ferrite, lanthanum carbonate, lead zirconate, titanate, magnesium diboride, porcelain, sialon, silicon carbide, silicon nitride, titanium carbide, yttrium barium copper oxide, zinc oxide, zirconium dioxide, and partially stabilised zirconia. In certain embodiments, the term "clinically significant increase" as used herein in connection with a treatment refers to a treatment that improves or provides a worthwhile change in an individual from a dysfunctional state back to a relatively normal functioning state, or moves themeasurement of that state in the direction of normal functioning, or at least a marked improvement to untreated. A number of methods can be used to calculate clinical significance. A non-exhaustive list of methods for calculating clinical significance includes: Jacobson-Truax, Gulliksen-Lord-Novick, Edwards-Nunnally, Hageman- Arrindell, and Hierarchical Linear Modeling (HLM).

[0081] The term "crosslink density" denotes the average number ofconnections of the amine containing repeat unit to the rest of the polymer. The number of connections can be 2, 3, 4 and higher. Repeat units in linear, non-crossl inked polymers are incorporated via 2 connections. To form an insoluble gel, the number of connections should be greater than 2. Low crosslinking density materials such as sevelamer have on average about 2.1 connections between repeat units. More crosslinked systems such as bixalomer have on average about 4.6 connections between the amine-containing repeat units. "Crosslinking density" represents a semiquantitative measure based on the ratios of the starting materials used. Limitations include the fact that it does not account for different crosslinking and polymerization methods. For example, small molecule amine systems require higher amounts of crosslinker as the crosslinker also serves as the monomer to form the polymer backbone whereas for radical polymerizations the polymer chain is formed independent from the crosslinking reaction. This can lead to inherently higher crosslinking densities under this definition for the substitution polymerization / small molecule amines as compared to radical polymerization crosslinked materials.

[0082] The term "crosslinker" as used, either alone or within other terms, encompasses hydrocarbyl or substituted hydrocarbyl, linear or branched molecules capable of reacting with any of the described monomers, or the infinite polymer network,as described in Formula 1 , more than one time. The reactive group in the crosslinker can include, but is not limited to alkyl halide, epoxide, phosgene, anhydride, carbamate, carbonate, isocyanate, thioisocyanate, esters, activated esters, carboxylic acids and derivatives, sulfonates and derivatives, acyl halides, aziridines, α,β-unsaturated carbonyls, ketones, aldehydes, pentafluoroaryl groups, vinyl, allyl, acrylate,methacrylate, acrylamide, methacrylamide, styrenic, acrylonitriles and combinations thereof. In one exemplary embodiment, the crosslinker's reactive group will include alkyl halide, epoxide, anhydrides, isocyanates, allyl, vinyl, acrylamide, and combinations thereof. In one such embodiment, the crosslinker's reactive group will be alkyl halide, epoxide, or allyl.

[0083] The term "diallylamine" denotes an amino moiety having two allyl groups.

[0084] The terms "dry bead" and "dry polymer" refer to beads or polymers that contain no more than 5% by weight of a non-polymer swelling agent or solvent. Often the swelling agent / solvent is water remaining at the end of a purification. This is generally removed by lyophilization or oven drying before storage or further crosslinking of a preformed amine polymer. The amount of swelling agent / solvent can be measured by heating (e.g., heating to 100-200°C) and measuring the resulting change in weight. This is referred to a "loss on drying" or "LOD."

[0085] The term "estimated glomerular filtration rate" or eGFR refers to an estimate of the glomerular filtration rate and is estimated from the serum level of an endogenous filtration marker. Creatinine is a commonly used endogenous filtration marker in clinical practice and several equations have been proposed for estimating the glomerular filtration rate. As used herein, all eGFR values may be determined according to the CKD-EPI equation (Levey et al., A New Equation to Estimate Glomerular Filtration Rate. Ann Intern Med. 2009; 150:604-612):GFR= 41*min(Scr / K, 1 )a *max(Scr / K, 1 )"1 209 *0.993Age *1.018 [if female]*1 .159 [if black]wherein Scr is serum creatinine (mg / dL), κ is 0.7 for females and 0.9 for males, a is - 0.329 for females and -0.41 1 for males, min indicates the minimum of Scr / κ or 1 , and max indicates the maximum of Scr / κ or 1 .

[0086] The term "ethereal" denotes a moiety having an oxygen bound to two separate carbon atoms as depicted the structural formula*-HxC-0-CHx-*, where*denotes the point of attachment to the remainder of the moiety and x independently equals 0, 1 , 2, or 3.

[0087] The term "gel" is used to describe a crosslinked polymer that has an irregular shape.

[0088] The term "glomerular filtration rate" or GFR is the volume of fluid filtered from the renal (kidney) glomerular capillaries into the Bowman's capsule per unit time. GFR cannot be measured directly; instead, it is measured indirectly (mGFR) as the clearance of an exogenous filtration marker (e.g., inulin, iothalamate, iohexol, etc.) or estimated (eGFR) using an endogenous filtration marker.

[0089] The term "halo" means halogens such as fluorine, chlorine, bromine or iodine atoms.

[0090] The term "haloalkyl group" encompasses groups wherein any one or more of the alkyl carbon atoms is substituted with halo as defined above. Specifically encompassed are monohaloalkyl, dihaloalkyl and polyhaloalkyl groups including perhaloalkyl. A monohaloalkyl group, for example, may have either an iodo, bromo, chloro or fluoro atom within the group. Dihalo and polyhaloalkyl groups may have two or more of the same halo atoms or a combination of different halo groups. "Lower haloalkyl group" encompasses groups having 1 -6 carbon atoms. In someembodiments, lower haloalkyl groups have one to three carbon atoms. Examples of haloalkyl groups include fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl, pentafluoroethyl, heptafluoropropyl,difluorochloromethyl, dichlorofluoromethyl, difluoroethyl, difluoropropyl, dichloroethyl and dichloropropyl.

[0091] The term "heteroaliphatic" describes a chain of 1 to 25 carbon atoms, typically 1 to 12 carbon atoms, more typically 1 to 10 carbon atoms, and most typically 1 to 8 carbon atoms, and in some embodiments 1 to 4 carbon atoms that can be saturated or unsaturated (but not aromatic), containing one or more heteroatoms, suchas halogen, oxygen, nitrogen, sulfur, phosphorus, or boron. A heteroatom atom may be a part of a pendant (or side) group attached to a chain of atoms (e.g. , -CH(OH)- - CH(NH2)- where the carbon atom is a member of a chain of atoms) or it may be one of the chain atoms (e.g. , -ROR- or -RNHR- where each R is aliphatic). Heteroaliphatic encompasses heteroalkyl and heterocyclo but does not encompass heteroaryl.

[0092] The term "heteroalkyl" describes a fully saturated heteroaliphatic moiety.

[0093] The term "heteroaryl" means a monocyclic or bicyclic aromatic radical of 5 to 10 ring atoms, unless otherwise stated, where one or more, (in one embodiment, one, two, or three), ring atoms are heteroatom selected from N, O, or S, the remaining ring atoms being carbon. Representative examples include, but are not limited to, pyrrolyl, thienyl, thiazolyl, imidazolyl, furanyl, indolyl, isoindolyl, oxazolyl, isoxazolyl, benzothiazolyl, benzoxazolyl, quinolinyl, isoquinolinyl, pyridinyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazolyl, tetrazolyl, and the like. As defined herein, the terms "heteroaryl" and "aryl" are mutually exclusive. "Heteroarylene" means a divalent heteroaryl radical.

[0094] The term "heteroatom" means an atom other than carbon and hydrogen. Typically, but not exclusively, heteroatoms are selected from the group consisting of halogen, sulfur, phosphorous, nitrogen, boron and oxygen atoms. Groups containing more than one heteroatom may contain different heteroatoms.

[0095] The term "heterocyclo," "heterocyclic," or heterocyclyl" means a saturated or unsaturated group of 4 to 8 ring atoms in which one or two ring atoms are heteroatom such as N, O, B, P and S(0)n, where n is an integer from 0 to 2, the remaining ring atoms being carbon. Additionally, one or two ring carbon atoms in the heterocyclyl ring can optionally be replaced by a -C(O)- group. More specifically the term heterocyclyl includes, but is not limited to, pyrrolidino, piperidino, homopiperidino, 2-oxopyrrolidinyl, 2-oxopiperidinyl, morpholino, piperazino, tetrahydro-pyranyl, thiomorpholino, and the like. When the heterocyclyl ring is unsaturated it can contain one or two ring double bonds provided that the ring is not aromatic. When the heterocyclyl group contains at least one nitrogen atom, it is also referred to herein as heterocycloamino and is a subset of the heterocyclyl group.

[0096] The term "hydrocarbon group" or "hydrocarbyl group" means a chain of 1 to 25 carbon atoms, typically 1 to 12 carbon atoms, more typically 1 to 10 carbonatoms, and most typically 1 to 8 carbon atoms. Hydrocarbon groups may have a linear or branched chain structure. Typical hydrocarbon groups have one or two branches, typically one branch. Typically, hydrocarbon groups are saturated. Unsaturated hydrocarbon groups may have one or more double bonds, one or more triple bonds, or combinations thereof. Typical unsaturated hydrocarbon groups have one or two double bonds or one triple bond; more typically unsaturated hydrocarbon groups have one double bond .

[0097] "Initiator" is a term used to describe a reagent that initiates a polymerization.

[0098] The term "measured glomerular filtration rate" or "mGFR" refers to a measurement of the glomerular filtration rate using any chemical (e.g., inulin, iothalamate, iohexol, etc.) that has a steady level in the blood, and is freely filtered but neither reabsorbed nor secreted by the kidneys according to standard technique.

[0099] The term "Michael acceptor" takes its normal meaning in the art. In certain embodiments the term "Michael acceptor" refers to activated olefins, such as α,β-unsaturated carbonyl compounds. A Michael acceptor can be a conjugated system with an electron withdrawing group, such as cyano, keto or ester. A non-exhaustive list of examples of Michael acceptors includes: vinyl ketones, alkyl acrylates, acrylo nitrile, and fumarates.

[0100] The term "molecular weight per nitrogen" or "MW / N" represents the calculated molecular weight in the polymer per nitrogen atom. It represents the average molecular weight to present one amine function within the crosslinked polymer. It is calculated by dividing the mass of a polymer sample by the moles of nitrogen present in the sample. "MW / N" is the inverse of theoretical capacity, and the calculations are based upon the feed ratio, assuming full reaction of crosslinker and monomer. The lower the molecular weight per nitrogen the higher the theoretical capacity of the crosslinked polymer.

[0101] The term "nonabsorbable" as used herein takes its normal meaning in the art. Therefore, if something is nonabsorbable it is not absorbed during its passage through the human Gl tract. This could be measured by any appropriate means. One option known to the skilled person would be to examine faeces to see if thenonabsorbable material is recovered after passing through the Gl tract. As a practicalmatter, the amount of a nonabsorbable material recovered in this scenario will never be 100% of the material administered. For example, about 90 - 99% of the material might be recovered from the faeces. Another option known to the skilled person would be to look for the presence of the material in the lynph, blood, interstitial fluid, secretions from various organs (eg, pancreas, liver, gut, etc) or in the body of organs (eg, liver, kidney, lungs, etc) as oral administration of a nonabsorbable material would not result in an increase in the amount of that material in these matrices and tissues. Nonabsorbable compositions may be particulate compositions that are essentially insoluble in the human Gl tract and have a particle size that is large enough to avoid passive or active absorption through the human Gl tract. As an example, nonabsorbable compositions is meant to imply that the substance does not enter the lymph, blood, interstitial fluids or organs through the main entry points of the human Gl tract, namely by paracellular entry between gut epithelial cells, by endocytic uptake through gut epithelial cells, or through entry via M cells comprising the gut epithelial antigen sampling and immune surveillance system (Jung, 2000), either through active or passive transportprocesses. There is a known size limit for a particulate to be absorbed in the human Gl tract (Jung et al., European Journal of Pharmaceutics and Biopharmaceutics 50 (2000) 147-160; Jani et al., Internation Journal of Pharmaceutics, 84 (1992) 245-252; and Jani et al., J. Pharm. Pharmacol. 1989, 41 :809-812), so the skilled person would know that materials that, when in the Gl tract, have a size of at least 1 micrometers would be nonabsorbable.

[0102] Optional" or "optionally" means that the subsequently described event or circumstance may but need not occur, and that the description includes instances where the event or circumstance occurs and instances in which it does not. For example, "heterocyclyl group optionally substituted with an alkyl group" means that the alkyl may but need not be present, and the description includes embodiments in which the heterocyclyl group is substituted with an alkyl group and embodiments in which the heterocyclyl group is not substituted with alkyl.

[0103] "Particle size" is measured by wet laser diffraction using Mie theory. Particles are dispersed in an appropriate solvent, such as water or methanol, and added to the sample chamber to achieve red channel obscuration of 10-20%. Sonication may be performed, and a dispersing agent, such as a surfactant (e.g. Tween-80), may be added in order to disrupt weak particle-particle interactions. The refractive index settingof the particles used for size distribution calculation is selected to minimize artifacts in the results and the R parameter value, determined by the laser diffraction software. The D(0.1 ), D(0.5), and D(0.9) values characterizing the particle size distribution by volume- basis are recorded.

[0104] "Pharmaceutically acceptable" as used in connection with a carrier, diluent or excipient means a carrier, diluent or an excipient, respectively, that is useful in preparing a pharmaceutical composition that is generally safe, non-toxic and neither biologically nor otherwise undesirable for veterinary use and / or human pharmaceutical use.

[0105] The term "post polymerization crosslinking" is a term that describes a reaction to an already formed bead or gel, where more crosslinking is introduced to the already formed bead or gel to create a bead or gel that has an increased amount of crosslinking.

[0106] The term "post polymerization modification" is a term that describes a modification to an already formed bead or gel, where a reaction or a treatment introduces an additional functionality. This functionality can be linked either covalently or non-covalently to the already formed bead.

[0107] The term "quaternized amine assay" ("QAA") describes a method to estimate the amount of quaternary amines present in a given crosslinked polymer sample. This assay measures chloride binding of a crosslinked polymer at a pH of 1 1 .5. At this pH, primary, secondary and tertiary amines are not substantially protonated and do not substantially contribute to chloride binding. Therefore, any binding observed under these conditions can be attributed to the presence of permanently charged quaternary amines. The test solution used for QAA assay is 100 mM sodium chloride at a pH of 1 1.5. The concentration of chloride ions is similar to that in the SGF assay which is used to assess total binding capacity of crosslinked polymers. Quaternary amine content as a percentage of total amines present is calculated as follows:„, _ , Chloride bound (mmol / g) in QAA „% Quaternary amines = chloride bound (mmol / g) in SGFX 1 00To perform the QAA assay, the free-amine polymer being tested is prepared at a concentration of 2.5 mg / ml (e.g. 25 mg dry mas) in 10 mL of QAA buffer. The mixture is incubated at 37 °C for ~16 hours with agitation on a rotisserie mixer. After incubationand mixing, 600 microliters of supernatant is removed and filtered using a 800microliter, 0.45 micrometer pore size, 96-well poly propylene filter plate. With the samples arrayed in the filter plate and the collection plate fitted on the bottom, the unit is centrifuged at 1000Xg for 1 minute to filter the samples. After filtration into the collection plate, the respective filtrates are diluted appropriately before measuring for chloride content. The IC method (e.g. ICS-2100 Ion Chromatography, Thermo Fisher Scientific) used for the analysis of chloride content in the filtrates consists of a 15 mM KOH mobile phase, an injection volume of 5 microliters, with a run time of three minutes, awashing / rinse volume of 1000 microliters, and flow rate of 1.25 ml_ / min. To determine the chloride bound to the polymer, the following calculation is completed:(CI start - CI eq)Binding capacity expressed as mmol chloride / g dry polymer =2 5where CI start corresponds to the starting concentration of chloride in the QAA buffer, CI eq corresponds to the equilibrium value of chloride in the measured filtrates after exposure to the test polymer, and 2.5 is the polymer concentration in mg / ml.

[0108] The terms "short chain carboxylic acid" or "short chain fatty acid" take their normal meaning in the art. In certain embodiments, the terms "short chain carboxylic acid" or "short chain fatty acid" refer to carboxylic acids having a chain length of 0, 1 , 2, 3, 4, 5 or 6 carbon atoms long. A non-exhaustive list of examples of short chain carboxylic acids includes: formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, and lactic acid.

[0109] "Simulated Gastric Fluid" or "SGF" Assay describes a test to determine total chloride binding capacity for a test polymer using a defined buffer that simulates the contents of gastric fluid as follows: Simulated gastric fluid (SGF) consists of 35 mM NaCI, 63 mM HCI, pH 1 .2. To perform the assay, the free-amine polymer being tested is prepared at a concentration of 2.5 mg / ml (25 mg dry mass) in 10 mL of SGF buffer. The mixture is incubated at 37 °C overnight for ~12-16 hours with agitation on a rotisserie mixer. Unless another time period is otherwise stated, SGF binding data or binding capacities recited herein are determined in a time period of this duration. After incubation and mixing, the tubes containing the polymer are centrifuged for 2 minutes at 500-1 OOOXg to pellet the test samples. Approximately 750 microliters of supernatant are removed and filtered using an appropriate filter, for example a 0.45 micrometer pore-size syringe filter or an 800 microliter, 1 micrometer pore-size, 96-well, glass filterplate that has been fitted over a 96-well 2 ml_ collection plate. With the latter arrangement, multiple samples tested in SGF buffer can be prepared for analysis, including the standard controls of free amine sevelamer, free amine bixalomer and a control tube containing blank buffer that is processed through all of the assay steps. With the samples arrayed in the filter plate and the collection plate fitted on the bottom, the unit is centrifuged at 1000Xg for 1 minute to filter the samples. In cases of small sample sets, a syringe filter may be used in lieu of the filter plate, to retrieve ~2-4 mL of filtrate into a 15 mL container. After filtration, the respective filtrates are diluted 4X with water and the chloride content of the filtrate is measured via ion chromatography (IC). The IC method (e.g. Dionex ICS-2100, Thermo Scientific) consists of an AS1 1 column and a 15 mM KOH mobile phase, an injection volume of 5 microliters, with a run time of 3 minutes, a washing / rinse volume of 1000 microliters, and flow rate of 1 .25 mL / min. To determine the chloride bound to the polymer, the following calculation is completed:(CI start - CI eg) x 42.5 Binding capacity expressed as mmol chloride / g polymer: where CI start corresponds to the starting concentration of chloride in the SGF buffer, CI eq corresponds to the equilibrium value of chloride in the diluted measured filtrates after exposure to the test polymer, 4 is the dilution factor and 2.5 is the polymer concentration in mg / ml.

[0110] "Simulated Small Intestine Inorganic Buffer" or "SIB" is a test to determine the chloride and phosphate binding capacity of free amine test polymers in a selective specific interfering buffer assay (SIB). The chloride and phosphate binding capacity of free amine test polymers, along with the chloride and phosphate binding capacity of free amine sevelamer and bixalomer control polymers, was determined using the selective specific interfering buffer assay (SIB) as follows: The buffer used for the SIB assay comprises 36 mM NaCI, 20 mM NaH2PO4, 50 mM 2-(N- morpholino)ethanesulfonic acid (MES) buffered to pH 5.5. The SIB buffer contains concentrations of chloride, phosphate and pH that are present in the human duodenum and upper gastrointestinal tract (Stevens T, Conwell DL, Zuccaro G, Van Lente F, Khandwala F, Purich E, et al. Electrolyte composition of endoscopically collected duodenal drainage fluid after synthetic porcine secretin stimulation in healthy subjects. Gastrointestinal endoscopy. 2004;60(3):351 -5, Fordtran J, Lockiear T. Ionic constituents and osmolality of gastric and small-intestinal fluids after eating. Digest Dis Sci.1966; 1 1 (7):503-21 ) and is an effective measure of the selectivity of chloride binding compared to phosphate binding by a polymer. To perform the assay, the free amine polymer being tested is prepared at a concentration of 2.5 mg / ml (25 mg dry mass) in 10 mL of SIB buffer. The mixture is incubated at 37 °C for 1 hour with agitation on a rotisserie mixer. Unless another time period is otherwise stated, SIB binding data or binding capacities recited herein are determined in a time period of this duration. After incubation and mixing, the tubes containing the polymer are centrifuged for 2 minutes at 1000Xg to pellet the test samples. 750 microliter of supernatant is removed and filtered using an 800 microliter, 1 micrometer pore-size, 96-well, glass filter plate that has been fitted over a 96-well 2 mL collection plate; with this arrangement multiple samples tested in SIB buffer can be prepared for analysis, including the standard controls of free amine sevelamer, free amine bixalomer and a control tube containing blank buffer that is processed through all of the assay steps. With the samples arrayed in the filter plate and the collection plate fitted on the bottom, the unit is centrifuged at 1000Xg for 1 minute to filter the samples. In cases of small sample sets, a syringe filter (0.45 micrometer) may be used in lieu of the filter plate, to retrieve ~2-4 mL of filtrate into a 15 mL vial. After filtration into the collection plate, the respective filtrates are diluted before measuring for chloride or phosphate content. For the measurement of chloride and phosphate, the filtrates under analysis are diluted 4X with water. The chloride and phosphate content of the filtrate is measured via ion chromatography (IC). The IC method (e.g. Dionex ICS-2100, Thermo Scientific) consists of an AS24A column, a 45 mM KOH mobile phase, an injection volume of 5 microliters, with a run time of about 10 minutes, a washing / rinse volume of 1000 microliter, and flow rate of 0.3 mL / min. To determine the chloride bound to the polymer, the following calculation is completed:(Clstart ~ Clfinal)x4Binding capacity expressed as mmol chloride / g polymer =2 5where C tait corresponds to the starting concentration of chloride in the SIB buffer, Clfmai corresponds to the final value of chloride in the measured diluted filtrates after exposure to the test polymer, 4 is the dilution factor and 2.5 is the polymer concentration in mg / ml. To determine the phosphate bound to the polymer, the following calculation iscompleted:(Pstart ~ Pfinal)x4Binding capacity expressed as mmol phosphate / g polymer =2 5where Pstait corresponds to the starting concentration of phosphate in the SIB buffer, Pfinai corresponds to the final value of phosphate in the measured diluted filtrates after exposure to the test polymer, 4 is the dilution factor and 2.5 is the polymerconcentration in mg / ml.

[0111] In certain embodiments, the term "statistically significant" refers to the likelikhood that a relationship between two or more variables is caused by something other than random chance. More precisely, the significance level, a, defined for a study is the probability of the study rejecting the null hypothesis, given that it were true, and the p-value, p, of a result is the probability of obtaining a result at least as extreme, given that the null hypothesis were true. The result is statistically significant, by the standards of the study, when p < a. The significance level for a study is chosen before data collection, and typically set to 5%

[0112] The term "substituted hydrocarbyl," "substituted alkyl," "substituted alkenyl," "substituted aryl," "substituted heterocyclo," or "substituted heteroaryl" as used herein denotes hydrocarbyl, alkyl, alkenyl, aryl, heterocyclo, or heteroaryl moieties which are substituted with at least one atom other than carbon and hydrogen, including moieties in which a carbon chain atom is substituted with a hetero atom such as nitrogen, oxygen, silicon, phosphorous, boron, sulfur, or a halogen atom. These substituents include halogen, heterocyclo, alkoxy, alkenoxy, alkynoxy, aryloxy, hydroxy, keto, acyl, acyloxy, nitro, amino, amido, nitro, cyano, thiol, ketals, acetals, esters and ethers.

[0113] "Swelling Ratio" or simply "Swelling" describes the amount of water absorbed by a given amount of polymer divided by the weight of the polymer aliquot. The Swelling Ratio is expressed as: swelling = (g swollen polymer - g dry polymer) / g dry polymer. The method used to determine the Swelling Ratio for any given polymer comprised the following: a. 50-100 mg of dry (less than 5 wt % water content) polymer is placed into an 1 1 ml_ sealable test tube (with screw cap) of known weight (weight of tube = Weight A).b. Deionized water (10ml_) is added to the tube containing the polymer. The tube is sealed and tumbled for 16 hours (overnight) at room temperature. After incubation, the tube is centrifuged at 3000xg for 3 minutes and the supernatant is carefully removed by vacuum suction. For polymers that form a very loose sediment, another step of centrifugation is performed.c. After step (b), the weight of swollen polymer plus tube (Weight B) is recorded. d. Freeze at -40 °C for 30 minutes. Lyophilize for 48 h. Weigh dried polymer and test tube (recorded as Weight C).e. Calculate g water absorbed per g of polymer, defined as: [(Weight B-Weight A)-(Weight C - Weight A)] / ( Weight C - Weight A).

[0114] A "target ion" is an ion to which the polymer binds, and usually refers to the major ions bound by the polymer, or the ions whose binding to the polymer is thought to produce the therapeutic effect of the polymer (e.g., proton and chloride binding which leads to net removal of HCI).

[0115] The term "theoretical capacity" represents the calculated, expected binding of hydrochloric acid in an "SGF" assay, expressed in mmol / g. The theoretical capacity is based on the assumption that 100 % of the amines from the monomer(s) and crosslinker(s) are incorporated in the crosslinked polymer based on their respective feed ratios. Theoretical capacity is thus equal to the concentration of aminefunctionalities in the polymer (mmol / g). The theoretical capacity assumes that each amine is available to bind the respective anions and cations and is not adjusted for the type of amine formed (e.g. it does not subtract capacity of quaternary amines that are not available to bind proton).

[0116] "Therapeutically effective amount" means the amount of a proton- binding crosslinked polymer that, when administered to a patient for treating a disease, is sufficient to effect such treatment for the disease. The amount constituting a"therapeutically effective amount" will vary depending on the polymer, the severity of the disease and the age, weight, etc., of the mammal to be treated.

[0117] "Treating" or "treatment" of a disease includes (i) inhibiting the disease, i.e., arresting or reducing the development of the disease or its clinical symptoms; or (ii) relieving the disease, i.e., causing regression of the disease or its clinical symptoms. Inhibiting the disease, for example, would include prophylaxis.

[0118] The term "triallylamine" denotes an amino moiety having three allyl groups.

[0119] The term "vinyl" denotes a moiety having the structural formulaRxHyC=CH-*where*denotes the point of attachment of the moiety to the remainder of the molecule wherein the point of attachment is a heteroatom or aryl, X and Y are independently 0, 1 or 2, such that X+Y=2, and R is hydrocarbyl or substitutedhydrocarbyl.

[0120] The term "weight percent crosslinker" represents the calculated percentage, by mass, of a polymer sample that is derived from the crosslinker. Weight percent crosslinker is calculated using the feed ratio of the polymerization, and assumes full conversion of the monomer and crosslinker(s). The mass attributed to thecrosslinker is equal to the expected increase of molecular weight in the infinite polymer network after reaction (e.g., 1 ,3-dichloropropane is 1 13 amu, but only 42 amu are added to a polymer network after crosslinking with DCP because the chlorine atoms, as leaving groups, are not incorporated into the polymer network).

[0121] When introducing elements of the present invention or the preferred embodiments(s) thereof, the articles "a", "an", "the" and "said" are intended to mean that there are one or more of the elements. The terms "comprising", "including" and "having" are intended to be inclusive and not exclusive (i.e., there may be other elements in addition to the recited elements).EMBODIMENTS

[0122] In accordance with the present disclosure, acid-base disorders may be treated using pharmaceutical compositions comprising a nonabsorbable composition having the capacity to remove clinically significant quantities of protons, the conjugate base of one or more strong acids, and / or one or more strong acids. An individual afflicted with a an acute or chronic acid / base disorder characterized by a baseline serum bicarbonate value of less than 22 mEq / l may thus be treated by oraladministration of a pharmaceutical composition comprising the nonabsorbable composition which then transits the individual's digestive system, binds a target species (protons, one or more conjugate base(s) of a strong acid and / or one or more strongacid(s)) as it transits the digestive system, and removes the bound target species by normal biological function (defecation).

[0123] In general, the individual afflicted with an acute or chronic acid / base disorder may be at any stage of chronic kidney disease. For example, in oneembodiment the afflicted individual has not yet reached end stage renal disease("ESRD") sometimes also referred to as end stage chronic kidney disease and is not yet on dialysis (i.e. , the individual has a mGFR (or eGFR) of at least 15 mL / min / 1 .73 m2). In some embodiments, the afflicted individual will be Stage 3B CKD (i.e. , the individual has a mGFR (or eGFR) in the range of 30-44 mL / min / 1 .73 m2for at least three months). In some embodiments, the afflicted individual will be Stage 3A CKD (i.e. , the individual has a mGFR (or eGFR) in the range of 45-59 mL / min / 1 .73 m2for at least three months). Thus, for example, in some embodiments the afflicted individual has a mGFR or an eGFR of less than 60 mL / min / 1 .73 m2for at least three months. By way of further example, in some embodiments the the afflicted individual has a mGFR or an eGFR of less than 45 mL / min / 1 .73 m2for at least three months. By way of further example, in some embodiments the the afflicted individual has a mGFR or an eGFR of less than 30 mL / min / 1 .73 m2for at least three months. By way of further example, in some embodiments the the afflicted individual has a mGFR or an eGFR of 15-30, 15-45, 15- 60, 30-45 or even 30-60 mL / min / 1 .73 m2for at least three months.

[0124] The baseline serum bicarbonate value may be the serum bicarbonate concentration determined at a single time point or may be the mean or median value of two or more serum bicarbonate concentrations determined at two or more time-points. For example, in one embodiment the baseline serum bicarbonate value may be the value of the serum bicarbonate concentration determined at a single time point and the baseline serum bicarbonate value is used as a basis to determine an acute acidic condition requiring immediate treatment. In another embodiment, the baseline serum bicarbonate treatment value is the mean value of the serum bicarbonate concentration for serum samples drawn at different time points (e.g. , different days). By way of further example, in one such embodiment the baseline serum bicarbonate treatment value is the mean value of the serum bicarbonate concentration for serum samples drawn on different days (e.g. , at least 2, 3, 4, 5 or more days, that may be consecutive or separated by one or more days or even weeks). By way of further example, in one such embodiment the baseline serum bicarbonate treatment value is the mean value of theserum bicarbonate concentration for serum samples drawn on two consecutive days preceding the initiation of treatment.

[0125] In one embodiment, the acid-base disorder being treated ischaracterized by a baseline serum bicarbonate value of less than 21 mEq / l. For example, in one such embodiment the acid-base disorder being treated is characterized by a baseline serum bicarbonate value of less than 20 mEq / l. By way of further example, in one such embodiment the acid-base disorder being treated is characterized by a baseline serum bicarbonate value of less than 19 mEq / l. By way of further example, in one such embodiment the acid-base disorder being treated is characterized by a baseline serum bicarbonate value of less than 18 mEq / l. By way of further example, in one such embodiment the acid-base disorder being treated is characterized by a baseline serum bicarbonate value of less than 17 mEq / l. By way of further example, in one such embodiment the acid-base disorder being treated is characterized by a baseline serum bicarbonate value of less than 16 mEq / l. By way of further example, in one such embodiment the acid-base disorder being treated is characterized by a baseline serum bicarbonate value of less than 15 mEq / l. By way of further example, in one such embodiment the acid-base disorder being treated is characterized by a baseline serum bicarbonate value of less than 14 mEq / l. By way of further example, in one such embodiment the acid-base disorder being treated is characterized by a baseline serum bicarbonate value of less than 13 mEq / l. By way of further example, in one such embodiment the acid-base disorder being treated is characterized by a baseline serum bicarbonate value of less than 12 mEq / l. By way of further example, in one such embodiment the acid-base disorder being treated is characterized by a baseline serum bicarbonate value of less than 1 1 mEq / l. By way of further example, in one such embodiment the acid-base disorder being treated is characterized by a baseline serum bicarbonate value of less than 10 mEq / l. By way of further example, in one such embodiment the acid-base disorder being treated is characterized by a baseline serum bicarbonate value of less than 9 mEq / l.

[0126] In general, however, the acid-base disorder being treated ischaracterized by a baseline serum bicarbonate value of at least 9 mEq / l. For example, in one such embodiment, the acid-base disorder is characterized by a baseline serum bicarbonate value of at least 10 mEq / l. By way of further example, in one such embodiment, the acid-base disorder is characterized by a baseline serum bicarbonatevalue of at least 1 1 mEq / l. By way of further example, in one such embodiment, the acid-base disorder is characterized by a baseline serum bicarbonate value of at least 12 mEq / l. By way of further example, in one such embodiment, the acid-base disorder is characterized by a baseline serum bicarbonate value of at least 13 mEq / l. By way of further example, in one such embodiment, the acid-base disorder is characterized by a baseline serum bicarbonate value of at least 14 mEq / l. By way of further example, in one such embodiment, the acid-base disorder is characterized by a baseline serum bicarbonate value of at least 15 mEq / l. By way of further example, in one such embodiment, the acid-base disorder is characterized by a baseline serum bicarbonate value of at least 16 mEq / l. By way of further example, in one such embodiment, the acid-base disorder is characterized by a baseline serum bicarbonate value of at least 17 mEq / l. By way of further example, in one such embodiment, the acid-base disorder is characterized by a baseline serum bicarbonate value of at least 18 mEq / l. By way of further example, in one such embodiment, the acid-base disorder is characterized by a baseline serum bicarbonate value of at least 19 mEq / l. By way of further example, in one such embodiment, the acid-base disorder is characterized by a baseline serum bicarbonate value of at least 20 mEq / l. By way of further example, in one such embodiment, the acid-base disorder is characterized by a baseline serum bicarbonate value of at least 21 mEq / l.

[0127] In certain embodiments, the acid-base disorder being treated is characterized by a baseline serum bicarbonate value in the range of 9 to 21 mEq / l. For example, in one such embodiment the acid-base disorder is characterized by a baseline serum bicarbonate value in the range of 12 to 20 mEq / l. By way of further example, in one such embodiment the acid-base disorder is characterized by a baseline serum bicarbonate value in the range of 12 to 19 mEq / l. By way of further example, in one such embodiment the acid-base disorder is characterized by a baseline serum bicarbonate value in the range of 12 to 18 mEq / l. By way of further example, in one such embodiment the acid-base disorder is characterized by a baseline serum bicarbonate value in the range of 12 to 17 mEq / l. By way of further example, in one such embodiment the acid-base disorder is characterized by a baseline serum bicarbonate value in the range of 12 to 16 mEq / l. By way of further example, in one such embodiment the acid-base disorder is characterized by a baseline serum bicarbonate value in the range of 9 to 1 1 mEq / l. By way of further example, in one suchembodiment the acid-base disorder is characterized by a baseline serum bicarbonate value in the range of 12-14. By way of further example, in one such embodiment the acid-base disorder is characterized by a baseline serum bicarbonate value in the range of 15-17. By way of further example, in one such embodiment the acid-base disorder is characterized by a baseline serum bicarbonate value in the range of 18-21 .

[0128] In certain embodiments, oral administration of a pharmaceutical composition containing a nonabsorbable composition increases the individual's serum bicarbonate value from baseline to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 1 mEq / l. For example, in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 1 .5 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 2 mEq / l. By way of further example in one such embodiment the treatment the individual's serumbicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 2.5 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least at least 3 mEq / l. By way of further example in one such embodiment the treatment increases the baseline serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 3.5 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 4 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 5 mEq / l but does not exceed 29 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 5 mEq / l but does not exceed 28 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baselineserum bicarbonate value by at least 5 mEq / l but does not exceed 27 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 5 mEq / l but does not exceed 26 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 6 mEq / l but does not exceed 29 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 6 mEq / l but does not exceed 28 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 6 mEq / l but does not exceed 27 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 6 mEq / l but does not exceed 26 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 7 mEq / l but does not exceed 29 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 7 mEq / l but does not exceed 28 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 7 mEq / l but does not exceed 27 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 7 mEq / l but does not exceed 26 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 8 mEq / l but does not exceed 29 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 8 mEq / l but does not exceed 28 mEq / l. By way offurther example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 8 mEq / l but does not exceed 27 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 8 mEq / l but does not exceed 26 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 9 mEq / l but does not exceed 29 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 9 mEq / l but does not exceed 28 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 9 mEq / l but does not exceed 27 mEq / l. By way of further example in one such embodiment the treatment increases the individual's serum bicarbonate value to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 9 mEq / l but does not exceed 26 mEq / l. In each of the foregoing exemplary embodiments recited in this paragraph, the treatment enables the increased serum bicarbonate value to be sustained over a prolonged period of at least one week, at least one month, at least two months, at least three months, at least six months, or even at least one year.

[0129] In certain embodiments, treatment with the nonabsorbable composition increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 20 mEq / l by at least 1 mEq / l. For example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 20 mEq / l by at least 1 .5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 20 mEq / l by at least 2 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 20 mEq / l by at least 2.5 mEq / l. By way of further example, in one such embodiment the treatment increases theindividual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 20 mEq / l by at least 3 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 20 mEq / l by at least 3.5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 20 mEq / l by at least 4 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 20 mEq / l by at least 4.5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 20 mEq / l by at least 5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 20 mEq / l by at least 5.5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 20 mEq / l by at least 6 mEq / l. In each of the foregoing exemplary embodiments recited in this paragraph, the increased serum bicarbonate value preferably does not exceed 29 mEq / l. For example, in each of the foregoing exemplary embodiments, the increased serum bicarbonate value may not exceed 28 mEq / l. By way of further example, in each of the foregoing exemplary embodiments, the increased serum bicarbonate value may not exceed 27 mEq / l. By way of further example, in each of the foregoing exemplary embodiments, the increased serum bicarbonate value may not exceed 26 mEq / l. Further, in each of the foregoing exemplary embodiments recited in this paragraph, the treatment enables the increased serum bicarbonate value to be sustained over a prolonged period of at least one week, at least one month, at least two months, at least three months, at least six months, or even at least one year.

[0130] In certain embodiments, treatment with the nonabsorbable composition increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 9 to 21 mEq / l by at least 1 mEq / l. For example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 9 to 21 mEq / l by at least 1 .5 mEq / l. By way of further example, in one such embodiment the treatment increases theindividual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 9 to 21 mEq / l by at least 2 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 9 to 21 mEq / l by at least 2.5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 9 to 21 mEq / l by at least 3 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 9 to 21 mEq / l by at least 3.5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 9 to 21 mEq / l by at least 4 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 9 to 21 mEq / l by at least 4.5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 9 to 21 mEq / l by at least 5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 9 to 21 mEq / l by at least 5.5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 9 to 21 mEq / l by at least 6 mEq / l. In each of the foregoing exemplary embodiments recited in this paragraph, the increased serum bicarbonate value preferably does not exceed 29 mEq / l. For example, in each of the foregoing exemplary embodiments, the increased serum bicarbonate value may not exceed 28 mEq / l. By way of further example, in each of the foregoing exemplary embodiments, the increased serum bicarbonate value may not exceed 27 mEq / l. By way of further example, in each of the foregoing exemplary embodiments, the increased serum bicarbonate value may not exceed 26 mEq / l. Further, in each of the foregoing exemplary embodiments recited in this paragraph, the treatment enables the increased serum bicarbonate value to be sustained over a prolonged period of at least one week, at least one month, at least two months, at least three months, at least six months, or even at least one year.

[0131] In certain embodiments, the acid-base disorder is treated with a pharmaceutical composition comprising the nonabsorbable composition and the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 14 mEq / l by at least 1 mEq / l. For example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 14 mEq / l by at least 1 .5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 14 mEq / l by at least 2 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 14 mEq / l by at least 2.5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 14 mEq / l by at least 3 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 14 mEq / l by at least 3.5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 14 mEq / l by at least 4 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 14 mEq / l by at least 4.5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 14 mEq / l by at least 5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 14 mEq / l by at least 6 mEq / l. By way of further example, in one such embodiment the treatment increases theindividual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 14 mEq / l by at least 7 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 14 mEq / l by at least 8 mEq / l. By way of further example, in one such embodiment the treatment increases theindividual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 14 mEq / l by at least 9 mEq / l. In each of the foregoing exemplaryembodiments recited in this paragraph, the increased serum bicarbonate value preferably does not exceed 29 mEq / l. For example, in each of the foregoing exemplary embodiments, the increased serum bicarbonate value may not exceed 28 mEq / l. By way of further example, in each of the foregoing exemplary embodiments, the increased serum bicarbonate value may not exceed 27 mEq / l. By way of further example, in each of the foregoing exemplary embodiments, the increased serum bicarbonate value may not exceed 26 mEq / l. Further, in each of the foregoing exemplary embodiments recited in this paragraph, the treatment enables the increased serum bicarbonate value to be sustained over a prolonged period of at least one week, at least one month, at least two months, at least three months, at least six months, or even at least one year.

[0132] In certain embodiments, the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 15 to 17 mEq / l by at least 1 mEq / l. For example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 15 to 17 mEq / l by at least 1.5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 15 to 17 mEq / l by at least 2 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 15 to 17 mEq / l by at least 2.5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 15 to 17 mEq / l by at least 3 mEq / l. By way of further example, in one such embodiment the treatment increases theindividual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 15 to 17 mEq / l by at least 3.5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 15 to 17 mEq / l by at least 4 mEq / l. By way of further example, in one such embodiment the treatment increases theindividual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 15 to 17 mEq / l by at least 4.5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 15 to 17 mEq / l by at least 5 mEq / l. By way of further example, in one such embodiment the treatment increases theindividual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 15 to 17 mEq / l by at least 6 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 15 to 17 mEq / l by at least 7 mEq / l. By way of further example, in one such embodiment the treatment increases theindividual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 15 to 17 mEq / l by at least 8 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 15 to 17 mEq / l by at least 9 mEq / l. In each of the foregoing exemplary embodiments recited in this paragraph, the increased serum bicarbonate value preferably does not exceed 29 mEq / l. For example, in each of the foregoing exemplary embodiments, the increased serum bicarbonate value may not exceed 28 mEq / l. By way of further example, in each of the foregoing exemplary embodiments, the increased serum bicarbonate value may not exceed 27 mEq / l. By way of further example, in each of the foregoing exemplary embodiments, the increased serum bicarbonate value may not exceed 26 mEq / l. Further, in each of the foregoing exemplary embodiments recited in this paragraph, the treatment enables the increased serum bicarbonate value to be sustained over a prolonged period of at least one week, at least one month, at least two months, at least three months, at least six months, or even at least one year.

[0133] In certain embodiments, the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 18 to 21 mEq / l by at least 1 mEq / l. For example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 18 to 21 mEq / l by at least 1.5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 18 to 21 mEq / l by at least 2 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 18 to 21 mEq / l by at least 2.5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 18 to 21 mEq / l by at least 3 mEq / l. By way of further example, in one such embodiment the treatment increases theindividual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 18 to 21 mEq / l by at least 3.5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 18 to 21 mEq / l by at least 4 mEq / l. By way of further example, in one such embodiment the treatment increases theindividual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 18 to 21 mEq / l by at least 4.5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 18 to 21 mEq / l by at least 5 mEq / l. By way of further example, in one such embodiment the treatment increases theindividual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 18 to 21 mEq / l by at least 5.5 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 18 to 21 mEq / l by at least 6 mEq / l. In each of the foregoing exemplary embodiments recited in this paragraph, the increased serum bicarbonate value preferably does not exceed 29 mEq / l. For example, in each of the foregoing exemplary embodiments, the increased serum bicarbonate value may not exceed 28 mEq / l. By way of further example, in each of the foregoing exemplary embodiments, the increased serum bicarbonate value may not exceed 27 mEq / l. By way of further example, in each of the foregoing exemplary embodiments, the increased serum bicarbonate value may not exceed 26 mEq / l. Further, in each of the foregoing exemplary embodiments recited in this paragraph, the treatment enables the increased serum bicarbonate value to be sustained over a prolonged period of at least one week, at least one month, at least two months, at least three months, at least six months, or even at least one year.

[0134] In certain embodiments, the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 21 mEq / l to an increased value in the range of 22 mEq / l to 26 mEq / l. For example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 17 mEq / l to an increased value in the range of 22 mEq / l to 26 mEq / l. By way of further example, in one suchembodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 12 to 14 mEq / l to an increased valuein the range of 22 mEq / l to 26 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 15 to 17 mEq / l to an increased value in the range of 22 mEq / l to 26 mEq / l. By way of further example, in one such embodiment the treatment increases the individual's serum bicarbonate value from a baseline serum bicarbonate value in the range of 18 to 21 mEq / l to an increased value in the range of 22 mEq / l to 26 mEq / l. In each of the foregoing embodiments recited in this paragraph, the treatment enables the increased serum bicarbonate value to be sustained over a prolonged period of at least one week, at least one month, at least two months, at least three months, at least six months, or even at least one year.

[0135] In certain embodiments, the treatment achieves a clinically significant increase is achieved within a treatment period of less than one month. For example, in one such embodiment, the treatment achieves a clinically significant increase within a treatment period of 25 days. By way of further example, in one such embodiment the treatment achieves the clinically significant increase is achieved within a treatment period of 3 weeks. By way of further example, in one such embodiment the treatment achieves the clinically significant increase is achieved within a treatment period of 15 days. By way of further example, in one such embodiment the treatment achieves the clinically significant increase is achieved within a treatment period of 2 weeks. By way of further example, in one such embodiment the treatment achieves the clinically significant increase is achieved within a treatment period of 10 days. By way of further example, in one such embodiment the treatment achieves the clinically significant increase is achieved within a treatment period of 1 week. By way of further example, in one such embodiment the treatment achieves the clinically significant increase is achieved within a treatment period of 6 days. By way of further example, in one such embodiment the treatment achieves the clinically significant increase is achieved within a treatment period of 5 days. By way of further example, in one such embodiment the treatment achieves the clinically significant increase is achieved within a treatment period of 4 days. By way of further example, in one such embodiment the treatment achieves the clinically significant increase is achieved within a treatment period of 3 days. By way of further example, in one such embodiment the treatment achieves the clinically significant increase is achieved within a treatment period of 2 days. By way of further example, in one such embodiment the treatment achieves the clinicallysignificant increase is achieved within a treatment period of 1 day. By way of further example, in one such embodiment the treatment achieves the clinically significant increase is achieved within a treatment period of 12 hours.

[0136] In certain embodiments, the treatment achieves a clinically significant increase is achieved without any change in the individual's diet or dietary habits relative to the period immediately preceding the initiation of treatment. For example, in one such embodiment the clinically significant increase is achieved independent of the individual's diet or dietary habits.

[0137] In certain embodiments, the individual's serum bicarbonate value returns to the baseline value ± 2.5 mEq / l within 1 month of the cessation of treatment. For example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2.5 mEq / l within 3 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2.5 mEq / l within 2 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2.5 mEq / l within 10 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2.5 mEq / l within 9 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2.5 mEq / l within 8 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2.5 mEq / l within 7 days of the cessation of treatment. By way of further example, in one suchembodiment the individual's serum bicarbonate value returns to the baseline value ± 2.5 mEq / l within 6 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2.5 mEq / l within 5 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2.5 mEq / l within 4 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2.5 mEq / l within 3 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2.5 mEq / l within 2 days of the cessation of treatment. Byway of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2.5 mEq / l within 1 day of the cessation of treatment.

[0138] In certain embodiments, the individual's serum bicarbonate value returns to the baseline value ± 2 mEq / l within 1 month of the cessation of treatment. For example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2 mEq / l within 3 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2 mEq / l within 2 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2 mEq / l within 10 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2 mEq / l within 9 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2 mEq / l within 8 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2 mEq / l within 7 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2 mEq / l within 6 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2 mEq / l within 5 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2 mEq / l within 4 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2 mEq / l within 3 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2 mEq / l within 2 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 2 mEq / l within 1 day of the cessation of treatment.

[0139] In certain embodiments, the individual's serum bicarbonate value returns to the baseline value ± 1 .5 mEq / l within 1 month of the cessation of treatment. For example, in one such embodiment the individual's serum bicarbonate value returnsto the baseline value ± 1.5 mEq / l within 3 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1 .5 mEq / l within 2 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1.5 mEq / l within 10 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1 .5 mEq / l within 9 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1.5 mEq / l within 8 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1 .5 mEq / l within 7 days of the cessation of treatment. By way of further example, in one suchembodiment the individual's serum bicarbonate value returns to the baseline value ± 1 .5 mEq / l within 6 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1 .5 mEq / l within 5 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1 .5 mEq / l within 4 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1.5 mEq / l within 3 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1 .5 mEq / l within 2 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1 .5 mEq / l within 1 day of the cessation of treatment.

[0140] In certain embodiments, the individual's serum bicarbonate value returns to the baseline value ± 1 mEq / l within 1 month of the cessation of treatment. For example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1 mEq / l within 3 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1 mEq / l within 2 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1 mEq / l within 10 days of the cessation oftreatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1 mEq / l within 9 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1 mEq / l within 8 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1 mEq / l within 7 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1 mEq / l within 6 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1 mEq / l within 5 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1 mEq / l within 4 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1 mEq / l within 3 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1 mEq / l within 2 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value returns to the baseline value ± 1 mEq / l within 1 day of the cessation of treatment.

[0141] In certain embodiments, upon the cessation of treatment theindividual's serum bicarbonate value decreases by at least 1 mEq / l within 1 month of the cessation of treatment. For example, in one such embodiment. For example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1 mEq / l within 3 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1 mEq / l within 2 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1 mEq / l within 10 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1 mEq / l within 9 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1 mEq / l within 8 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1mEq / l within 7 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1 mEq / l within 6 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1 mEq / l within 5 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1 mEq / l within 4 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1 mEq / l within 3 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1 mEq / l within 2 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1 mEq / l within 1 day of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1 mEq / l within 12 hours of the cessation of treatment.

[0142] In certain embodiments, upon the cessation of treatment the individual's serum bicarbonate value decreases by at least 1 .5 mEq / l within 1 month of the cessation of treatment. For example, in one such embodiment. For example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1.5 mEq / l within 3 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1.5 mEq / l within 2 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1.5 mEq / l within 10 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1.5 mEq / l within 9 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1.5 mEq / l within 8 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1.5 mEq / l within 7 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1.5 mEq / l within 6 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1.5mEq / l within 5 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1.5 mEq / l within 4 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1.5 mEq / l within 3 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1.5 mEq / l within 2 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1.5 mEq / l within 1 day of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 1.5 mEq / l within 12 hours of the cessation of treatment.

[0143] In certain embodiments, upon the cessation of treatment the individual's serum bicarbonate value decreases by at least 2 mEq / l within 1 month of the cessation of treatment. For example, in one such embodiment. For example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2 mEq / l within 3 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2 mEq / l within 2 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2 mEq / l within 10 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2 mEq / l within 9 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2 mEq / l within 8 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2 mEq / l within 7 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2 mEq / l within 6 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2 mEq / l within 5 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2 mEq / l within 4 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2mEq / l within 3 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2 mEq / l within 2 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2 mEq / l within 1 day of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2 mEq / l within 12 hours of the cessation of treatment.

[0144] In certain embodiments, upon the cessation of treatment the individual's serum bicarbonate value decreases by at least 2.5 mEq / l within 1 month of the cessation of treatment. For example, in one such embodiment. For example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2.5 mEq / l within 3 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2.5 mEq / l within 2 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2.5 mEq / l within 10 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2.5 mEq / l within 9 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2.5 mEq / l within 8 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2.5 mEq / l within 7 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2.5 mEq / l within 6 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2.5 mEq / l within 5 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2.5 mEq / l within 4 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2.5 mEq / l within 3 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2.5 mEq / l within 2 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2.5mEq / l within 1 day of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 2.5 mEq / l within 12 hours of the cessation of treatment.

[0145] In certain embodiments, upon the cessation of treatment the individual's serum bicarbonate value decreases by at least 3 mEq / l within 1 month of the cessation of treatment. For example, in one such embodiment. For example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3 mEq / l within 3 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3 mEq / l within 2 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3 mEq / l within 10 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3 mEq / l within 9 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3 mEq / l within 8 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3 mEq / l within 7 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3 mEq / l within 6 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3 mEq / l within 5 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3 mEq / l within 4 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3 mEq / l within 3 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3 mEq / l within 2 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3 mEq / l within 1 day of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3 mEq / l within 12 hours of the cessation of treatment.

[0146] In certain embodiments, upon the cessation of treatment the individual's serum bicarbonate value decreases by at least 3.5 mEq / l within 1 month of the cessation of treatment. For example, in one such embodiment. For example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3.5 mEq / l within 3 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3.5 mEq / l within 2 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3.5 mEq / l within 10 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3.5 mEq / l within 9 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3.5 mEq / l within 8 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3.5 mEq / l within 7 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3.5 mEq / l within 6 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3.5 mEq / l within 5 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3.5 mEq / l within 4 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3.5 mEq / l within 3 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3.5 mEq / l within 2 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3.5 mEq / l within 1 day of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 3.5 mEq / l within 12 hours of the cessation of treatment.

[0147] In certain embodiments, upon the cessation of treatment the individual's serum bicarbonate value decreases by at least 4 mEq / l within 1 month of the cessation of treatment. For example, in one such embodiment. For example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4mEq / l within 3 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4 mEq / l within 2 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4 mEq / l within 10 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4 mEq / l within 9 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4 mEq / l within 8 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4 mEq / l within 7 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4 mEq / l within 6 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4 mEq / l within 5 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4 mEq / l within 4 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4 mEq / l within 3 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4 mEq / l within 2 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4 mEq / l within 1 day of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4 mEq / l within 12 hours of the cessation of treatment.

[0148] In certain embodiments, upon the cessation of treatment the individual's serum bicarbonate value decreases by at least 4.5 mEq / l within 1 month of the cessation of treatment. For example, in one such embodiment. For example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4.5 mEq / l within 3 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4.5 mEq / l within 2 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least4.5 mEq / l within 10 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4.5 mEq / l within 9 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4.5 mEq / l within 8 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4.5 mEq / l within 7 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4.5 mEq / l within 6 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4.5 mEq / l within 5 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4.5 mEq / l within 4 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4.5 mEq / l within 3 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4.5 mEq / l within 2 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4.5 mEq / l within 1 day of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 4.5 mEq / l within 12 hours of the cessation of treatment.

[0149] In certain embodiments, upon the cessation of treatment the individual's serum bicarbonate value decreases by at least 5 mEq / l within 1 month of the cessation of treatment. For example, in one such embodiment. For example, in one such embodiment the individual's serum bicarbonate value decreases by at least 5 mEq / l within 3 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 5 mEq / l within 2 weeks of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 5 mEq / l within 10 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 5 mEq / l within 9 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 5mEq / l within 8 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 5 mEq / l within 7 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 5 mEq / l within 6 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 5 mEq / l within 5 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 5 mEq / l within 4 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 5 mEq / l within 3 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 5 mEq / l within 2 days of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 5 mEq / l within 1 day of the cessation of treatment. By way of further example, in one such embodiment the individual's serum bicarbonate value decreases by at least 5 mEq / l within 12 hours of the cessation of treatment.

[0150] In one embodiment, the baseline serum bicarbonate value is the value of the serum bicarbonate concentration determined at a single time point. In another embodiment, the baseline serum bicarbonate value is the mean value of at least two serum bicarbonate concentrations determined at different time-points. For example, in one such embodiment the baseline serum bicarbonate value is the mean value of at least two serum bicarbonate concentrations for serum samples drawn on different days. By way of further example, the baseline serum bicarbonate value is the mean or median value of at least two serum bicarbonate concentrations for serum samples drawn on non-consecutive days. By way of further example, in one such method the non- consecutive days are separated by at least two days. By way of further example, in one such method the non-consecutive days are separated by at least one week. By way of further example, in one such method the non-consecutive days are separated by at least two weeks. By way of further example, in one such method the non-consecutive days are separated by at least three weeks.

[0151] In certain embodiments, the daily dose is no more than 100 g / day of the nonabsorbable composition. For example, in one such embodiment the daily doseis no more than 90 g / day of the nonabsorbable composition. By way of further example, in one such embodiment the daily dose is no more than 75 g / day of the nonabsorbable composition. By way of further example, in one such embodiment the daily dose is no more than 65 g / day of the nonabsorbable composition. By way of further example, in one such embodiment the daily dose is no more than 50 g / day of the nonabsorbable composition. By way of further example, in one such embodiment the daily dose is no more than 40 g / day of the nonabsorbable composition. By way of further example, in one such embodiment the daily dose is no more than 30 g / day of the nonabsorbable composition. By way of further example, in one such embodiment the daily dose is no more than 25 g / day of the nonabsorbable composition. By way of further example, in one such embodiment the daily dose is no more than 20 g / day of the nonabsorbable composition. By way of further example, in one such embodiment the daily dose is no more than 15 g / day of the nonabsorbable composition. By way of further example, in one such embodiment the daily dose is no more than 10 g / day of the nonabsorbable composition. By way of further example, in one such embodiment the daily dose is no more than 5 g / day of the nonabsorbable composition.

[0152] In certain embodiments, the individual is treated with the daily dose for a period of at least one day. For example, in one such embodiment the individual is treated with the daily dose for a period of at least one week. By way of further example, in one such embodiment the individual is treated with the daily dose for a period of at least one month. By way of further example, in one such embodiment the individual is treated with the daily dose for a period of at least two months. By way of further example, in one such embodiment the individual is treated with the daily dose for a period of at least three months. By way of further example, in one such embodiment the individual is treated with the daily dose for a period of at least several months. By way of further example, in one such embodiment the individual is treated with the daily dose for a period of at least six months. By way of further example, in one such embodiment the individual is treated with the daily dose for a period of at least one year.

[0153] In certain embodiments of the method of the present disclosure, the daily dose of the nonabsorbable composition has the capacity to remove at least about 5 mEq / day of the target species. For example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 6 mEq / day of the target species. By way of further example, in one such embodiment the dailydose of the nonabsorbable composition has the capacity to remove at least about 7 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 8 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 9 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 10 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 1 1 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 12 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 13 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 14 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 15 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 16 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 17 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 18 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 19 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 20 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 21 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 22 mEq / day of the target species. By way of further example, in one such embodiment the daily doseof the nonabsorbable composition has the capacity to remove at least about 23 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 24 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 25 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 26 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 27 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 28 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 29 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 30 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 31 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 32 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 33 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 34 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 35 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 36 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 37 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 38 mEq / day of the target species. By way of further example, in one such embodiment the daily doseof the nonabsorbable composition has the capacity to remove at least about 39 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 40 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 41 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 42 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 43 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 44 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 45 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 46 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 47 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 48 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 49 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition has the capacity to remove at least about 50 mEq / day of the target species.

[0154] In certain embodiments of the method of the present disclosure, the daily dose of the nonabsorbable composition removes at least about 5 mEq / day of the target species. For example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 6 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition removes at least about 7 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition removes at least about 8 mEq / day of the target species. By way of further example, inone such embodiment the daily dose of the nonabsorbable composition removes at least about 9 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition removes at least about 10 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition removes at least about 1 1 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition removes at least about 12 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of the nonabsorbable composition removes at least about 13 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 14 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 15 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 16 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 17 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 18 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 19 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 20 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 21 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 22 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 23 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 24 mEq / day of the target species.By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 25 mEq / day of the target species.By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 26 mEq / day of the arget species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 27 mEq / day of the arget species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 28 mEq / day of the arget species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 29 mEq / day of the arget species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 30 mEq / day of the arget species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 31 mEq / day of the arget species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 32 mEq / day of the arget species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 33 mEq / day of the arget species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 34 mEq / day of the arget species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 35 mEq / day of the arget species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 36 mEq / day of the arget species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 37 mEq / day of the arget species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 38 mEq / day of the arget species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 39 mEq / day of the arget species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 40 mEq / day of the arget species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 41 mEq / day of the arget species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 42 mEq / day of the arget species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 43 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 44 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 45 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 46 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 47 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 48 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 49 mEq / day of the target species. By way of further example, in one such embodiment the daily dose of thenonabsorbable composition removes at least about 50 mEq / day of the target species.

[0155] In certain embodiments of the method of the present disclosure, the daily dose of the nonabsorbable composition removes less than 60 mEq / day of the target species. For example, in one such method the daily dose removes less than 55 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 50 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 45 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 40 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 35 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 34 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 33 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 32 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 31 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 30 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 29 mEq / day of the target species. By way of further example, in one such embodimentthe daily dose removes less than 28 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 27 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 26 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 25 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 24 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 23 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 22 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 21 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 20 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 19 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 18 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 17 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 16 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 15 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 14 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 13 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 12 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 1 1 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 10 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 9 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 8 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 7 mEq / day of the target species. By way of further example, in one such embodiment the daily dose removes less than 6 mEq / day of the target species.

[0156] In certain embodiments of the method of the present disclosure, the daily dose of the nonabsorbable composition has insufficient capacity to remove more than 60 mEq / day of the target species. For example, in one such method the daily dose has insufficient capacity to remove more than 55 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 50 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 45 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 40 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 35 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 34 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 33 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 32 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 31 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 30 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 29 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 28 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 27 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 26 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 25 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 24 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 23 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 22 mEq / day of the target species. By way of further example, in onesuch embodiment the daily dose has insufficient capacity to remove more than 21 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 20 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 19 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 18 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 17 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 16 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 15 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 14 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 13 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 12 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 1 1 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 10 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 9 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 8 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 7 mEq / day of the target species. By way of further example, in one such embodiment the daily dose has insufficient capacity to remove more than 6 mEq / day of the target species.

[0157] In certain embodiments of the method of the present disclosure, the method comprises oral administration of a pharmaceutical composition to increase the individual's serum bicarbonate levels wherein: (i) the pharmaceutical composition binds a target species in the individual's digestive system when given orally, the target species being selected from the group consisting of protons, strong acids, andconjugate bases of strong acids; and (ii) the pharmaceutical composition increases the serum bicarbonate level by at least 1 mEq / l in a placebo controlled study, said increase being the difference between the cohort average serum bicarbonate level in a first cohort at the end of the study, relative to the cohort average serum bicarbonate level in a second cohort at the end of the study, wherein the first cohort's subjects receive the pharmaceutical composition and the second cohort's subjects receive a placebo, wherein the first and second cohorts each comprise at least 25 subjects, each cohort is prescribed the same diet during the study and the study lasts at least two weeks. In one embodiment, the first cohort receives a daily dose of the pharmaceutical composition that does not exceed 100 g / day. In one embodiment, the first cohort receives a daily dose of the pharmaceutical composition that does not exceed 50 g / day. In one embodiment, the first cohort receives a daily dose of the pharmaceutical composition that does not exceed 30 g / day. In one embodiment, the first cohort receives a daily dose of the pharmaceutical composition that does not exceed 25 g / day. In one embodiment, the first cohort receives a daily dose of the pharmaceutical composition that does not exceed 20 g / day. In one embodiment, the first cohort receives a daily dose of the pharmaceutical composition that does not exceed 15 g / day. In one embodiment, the first cohort receives a daily dose of the pharmaceutical composition that does not exceed 10 g / day. In one embodiment, the first cohort receives a daily dose of the pharmaceutical composition that does not exceed 5 g / day. In one embodiment, the target species is protons. In one embodiment, the target species is chloride ions. In one embodiment, the target species is a strong acid. In oneembodiment, the target species is HCI. In one embodiment, the pharmaceutical composition is not absorbed when inqested.

[0158] In one embodiment, the individual or adult human patient has chronic kidney disease (CKD Stage 3 - 4; eGFR 20 - <60 mL / min / 1 .73m2) and a baseline serum bicarbonate value at the start of the study between 12 and 20 mEq / L. In one embodiment, the pharmaceutical composition increases the serum bicarbonate level of the the individual or adult human patient by at least 2 mEq / l in the placebo controlled study. In one embodiment, the pharmaceutical composition increases the serum bicarbonate level of the the individual or adult human patient by at least 3 mEq / l in the placebo controlled study. In one embodiment, the individual or adult human patient isnot yet in need for kidney replacement therapy (dialysis or transplant). In oneembodiment, the individual or adult human patient has not yet reached end stage renal disease ("ESRD").

[0159] In one embodiment, the individual or adult human patient has a mGFR of at least 15 mL / min / 1.73 m2In one embodiment, the individual or adult human patient has an eGFR of at least 15 mL / min / 1 .73 m2In one embodiment, the individual or adult human patient has a mGFR of at least 30 mL / min / 1 .73 m2. In one embodiment, the individual or adult human patient has an eGFR of at least 30 mL / min / 1 .73 m2. In one embodiment, the individual or adult human patient has a mGFR of less than 45 mL / min / 1 .73 m2for at least three months. In one embodiment, the individual or adult human patient has an eGFR of less than 45 mL / min / 1.73 m2for at least three months. In one embodiment, the individual or adult human patient has a mGFR of less than 60 mL / min / 1 .73 m2for at least three months. In one embodiment, the individual or adult human patient has an eGFR of less than 60 mL / min / 1.73 m2for at least three months. In one embodiment, the individual or adult human patient has Stage 3A CKD, Stage 3B CKD, or Stage 4 CKD.

[0160] While the methods described above refer to daily dose, a further aspect of the disclosure include the methods disclosed herein in which the dose is administered less frequently than once per day (while still being administered on a regular basis). In any of the disclosure, the daily dose specified may, instead, be administrated on a less frequent basis. For example, the doses disclosed here may be administered once every two or three days. Or the doses disclosed here may be administered once, twice or three times a week.

[0161] In addition to (or as a surrogate for) serum bicarbonate, other biomarkers of acid-base imbalance may be used as a measure of acid-base status. For example, blood (serum or plasma) pH, total CO2, anion gap, and / or the concentration of other electrolytes (e.g., sodium, potassium, calcium, magnesium, chloride and / or sulfate) may be used as an indicator of acid-base imbalance. Similarly, net acid excretion ("NAE"), urine pH, urine ammonium concentration, and / or the concentration of other electrolytes in the urine (e.g. , sodium, potassium, calcium, magnesium, chloride and / or sulfate) may be used as an indicator of acid-base imbalance.Fluid Biomarker Normal / Target Value Analytical Techniqueof interestBlood Total C0223 - 29 mmol / L Blood gas analyzer;(serum enzymatic assay; ion or selective electrodeplasma) Anion gap 3 - 1 1 mEq / L Obtained from standard chemistry electrolyte panelPH 7.36 to 7.44 Blood gas analyzer;enzymatic assay; ion selective electrodeElectrolytes Na = 135-145 mEq / L; Obtained from standardK = 3.5-5 mEq / L; chemistry electrolyte Total Ca = 8-10.5 mEq / L, panel;depending on age and sex;Mg = 1 .5 - 2.5 mEq / L, ion selective electrodes depending on age; can be used for Na, CI CI = 95-105 mEq / L; and Kphosphate = 2.5-4.5 mEq / L;sulfate = 1 mEq / Lurine PH 4.5 - 8.0 pH meterammonium 3 - 65 mmol / L Enzymaticcitrate 150 - 1 , 191 mg / 24-hour urine Enzymaticcollection; ranges for 20 to 60years of agesodium 20 mEq / L in spot samples, 41 Ion-selective electrode- 227 mEq / L per day(depending upon salt and fluidintake)potassium 17 - 77 mmol / 24 hours; spot Ion-selective electrode sample is ~45 mmol / Lcalcium Urinary calcium is <250 mg / 24 Enzymatichours in males, <200 mg / 24hours in femalesmagnesium Urinary magnesium is 51 - Enzymatic269 mg / 24 hours; spot valuesare usually reported as a ratiowith creatinine and are >0.035mg Mg / mg creatininechloride Urinary chloride is 40 - 224 Ion-selective electrode mmol / 24 hoursUrine Anion UAG = 0-10 mEq / L; UAG = (Na++ K+) - CI"inGap Metabolic acidosis indicated urine. It is a measure of("UAG") when UAG > 20 mEq / L ammonium excretion, the primary mechanism for acid excretion.Net Acid Urinary net acid excretion is 24-hour urine collectionExcretion the total amount of acid required; Direct NAEexcreted by the kidney per measurement (mEq / day) = day; the NAE value depends [NH4+] + [TA] - [HCO3-], on the age of the subject, where TA is concentration gender, and protein intake; of titratable acids typical NAE values range from

[0162] In one embodiment, treatment of an individual as described herein may improve an individuals' serum anion gap. For example, treating an acid base imbalance with a a neutral composition having the capacity to bind both protons and anions (unaccompanied by the delivery of sodium or potassium ions) can increase serum bicarbonate without an accompanying increase in sodium or potassium (see Example 3 and Figs 13A, 13C and 13D). Consequently, the serum anion gap may be improved (decreased) by at least 1 mEq / l or more (e.g., at least 2 mEq / l) within a period as short ast 2 weeks (see Example 3).

[0163] The various aspects and embodiments may have a range of advantages, such as improved or successful treatment of metabolic acidosis. Such improvements may also include reduced side effects, increased patient compliance, reduced drug loads, increased speed of treatment, increased magnitude of treatment, avoiding unwanted changes to other electrolytes and / or reduced drug-drug interactions. A further improvement may include reducing a patient's anion gap (as defined above) as part of the methods and other aspects disclosed herein. Further useful features of the disclosed aspects can be found in the examples.Certain specific compositions for use in treatment

[0164] As previously noted, one aspect disclosed here is a composition for use in a method of treating metabolic acidosis in an adult human patient wherein in said treatment 0.1 - 12 g of said composition is administered to the patient per day, said composition being a nonabsorbable composition having the capacity to remove protons from the patient, wherein the nonabsorbable composition is characterized by a chloride ion binding capacity of at least 2.5 mEq / g in a Simulated Small Intestine Inorganic("SIB") assay. This aspect is based on the data in the examples showing the absorption and removal of HCI to successfully treat patients, allowing the amount of thecomposition to be set based on its capacity to bind chloride in the SIB assay. As shown in the examples, a composition with this specified level of chloride binding in the "SIB"assay can be used in the specified dose range to successfully treat metabolic acidosis in adult humans. In this aspect, the composition may be administered orally, and so would be an orally administered nonabsorbable composition as defined herein.

[0165] This aspect is based on the data in the examples showing the absorption and removal of HCI to successfully treat patients using a composition according to this aspect, allowing the amount of the composition to be set based on its capacity to bind chloride in the SIB assay. Surprisingly, the amounts required for successful treatment were relatively low.

[0166] Another aspect of the present disclosure is a composition for use in a method of treating metabolic acidosis in an adult human patient by increasing that patient's serum bicarbonate value by at least 1 mEq / L over 15 days of treatment, said composition being a nonabsorbable composition having the capacity to remove protons from the patient. In this aspect, the composition may be administered orally, and so would be an orally administered nonabsorbable composition as defined herein.

[0167] This aspect is based on the data in the examples showing the absorption and removal of HCI to successfully treat patients using a composition according to this aspect which provides new detail regarding the reductions possible using a composition of the disclosure. This aspect includes surprisingly rapid increases in the patient's serum bicarbonate level, for example in the first few days, as well as surprisingly large increases in serum bicarbonate level.

[0168] Another aspect of the present disclosure is a composition for use in a method of treating metabolic acidosis in an adult human patient, said patient having a serum bicarbonate level of less than 20 mEq / L prior to treatment, said composition being a nonabsorbable composition having the capacity to remove protons from the patient. In this aspect, the composition may be administered orally, and so would be an orally administered nonabsorbable composition as defined herein.

[0169] This aspect is based on the data in the examples showing, for the first time, the successful treatment of patients with a low serum bicarbonate level, for example levels that have not been shown to be so readily treated previously. The patients with lower serum bicarbonate levels responded particularly well to the treatment and this improvement for this subgroup is one advantage of this aspect.

[0170] Another aspect of the present disclosure is a composition for use in a method of treating metabolic acidosis in an adult human patient by increasing that patient's serum bicarbonate value by at least 1 mEq / L over 15 days of treatment, wherein in said treatment >12 - 100g of said polymer is administered to the patient per day, said composition being a nonabsorbable composition having the capacity to remove protons from the patient, wherein the nonabsorbable composition ischaracterized by a chloride ion binding capacity of at least 2.5 mEq / g in a Simulated Small Intestine Inorganic Buffer ("SIB") assay. In this aspect, the composition may be administered orally, and so would be an orally administered nonabsorbable composition as defined herein.

[0171] Another aspect of the present disclosure is a composition for use in a method of treating metabolic acidosis in an adult human patient wherein in said treatment >12 - 100g of said composition is administered to the patient per day, said composition being a nonabsorbable composition having the capacity to remove protons from the patient, wherein the nonabsorbable composition is characterized by a chloride ion binding capacity of less than 2.5 mEq / g in a Simulated Small Intestine Inorganic Buffer ("SIB") assay. In this aspect, the composition may be administered orally, and so would be an orally administered nonabsorbable composition as defined herein.

[0172] The chloride ion binding capacity in the SIB assay is affected by both the composition's selectivity for binding chloride and the total space available for chloride binding. The term "composition" refers to the active pharmaceutical ingredient, including any counter ions, but not to excipients. So, the "amount" of the composition is the amount of active pharmaceutical ingredient without including other parts of any unit dose form.

[0173] More specifically in these aspects, the amount of composition may be any amount disclosed herein in other sections within the range 0.1 g - 12 g. For example, 1 - 1 1 g, 2 - 10 g, 3 - 9 g, 3 - 8 g, 3 - 7 g, 3 - 6 g, 3.5 - 5.5 g, 4 - 5 g, or 4.5 - 5 g of said polymer is administered to the patient per day, or 0.5 g, 1 g, 1 .5 g, 2 g, 2.5 g, 3 g, 3.5 g, 4.0 g, 4.5 g or 5.0 g of the composition is administered to the patient per day.

[0174] More specifically in these aspects, the chloride ion binding capacity in a Simulated Small Intestine Inorganic Buffer ("SIB") assay may be greater than 3, 3.5, 4,or 4.5 mEq / g. One upper limit for the chloride ion binding capacity in a SIB assay is 10 mEq / g. Other the upper limits may be 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 or 10 mEq / g, or there may be no upper limit specified.

[0175] All combinations of the amount of composition and the chloride ion binding capacity mentioned here are also disclosed. For example, in one embodiment, the composition has a chloride ion binding capacity in a SIB assay is of at least 4.5 mEq / g and only 0.1 - 6gs of composition is administered in the method of treating metabolic acidosis.

[0176] The composition in these aspects can additionally have any of the properties or features specified elsewhere herein. For example, the composition may be a nonabsorbable composition as described in the following section. In a similar fashion, the methods of treatment specified in these aspects may include any of the features disclosed in the preceding section regarding certain methods of treatment.Nonabsorbable Compositions

[0177] As previously noted, the nonabsorbable compositions having the medical uses described herein possess the capacity to remove clinically significant quantities of one or more target species: (i) protons, (ii) the conjugate base(s) of one or more strong acids (e.g., chloride, bisulfate (HSO4") and / or sulfate (SO4") ions) and / or (iii) one or more strong acids (e.g. , HCI and / or H2SO4). To bind such target species, the nonabsorbable compositions may be selected from the group consisting of cation exchange compositions, anion exchange compositions, amphoteric ion exchange compositions, neutral compositions having the capacity to bind both protons and anions, composites thereof and mixtures thereof.

[0178] In general, the nonabsorbable composition has a preferred particle size range that is (i) large enough to avoid passive or active absorption through the Gl tract and (ii) small enough to not cause grittiness or unpleasant mouth feel when ingested as a powder, sachet and / or chewable tablet / dosage form with a mean particle size of at least 3 microns. For example, in one such embodiment the nonabsorbable composition comprises a population of particles having a mean particle size (volume distribution) in the range of 5 to 1 ,000 microns. By way of further example, in one such embodiment the nonabsorbable composition comprises a population of particles having a mean particle size (volume distribution) in the range of 5 to 500 microns. By way offurther example, in one such embodiment the nonabsorbable composition comprises a population of particles having a mean particle size (volume distribution) in the range of 10 to 400 microns. By way of further example, in one such embodiment thenonabsorbable composition comprises a population of particles having a mean particle size (volume distribution) in the range of 10 to 300 microns. By way of further example, in one such embodiment the nonabsorbable composition comprises a population of particles having a mean particle size (volume distribution) in the range of 20 to 250 microns. By way of further example, in one such embodiment the nonabsorbable composition comprises a population of particles having a mean particle size (volume distribution) in the range of 30 to 250 microns. By way of further example, in one such embodiment the nonabsorbable composition comprises a population of particles having a mean particle size (volume distribution) in the range of 40 to 180 microns. In certain embodiments, less than 7% of the particles in the population (volume distribution) have a diameter less than 10 microns. For example, in such embodiments less than 5% of the particles in the particles in the population (volume distribution) have a diameter less than 10 microns. By way of further example, in such embodiments less than 2.5% of the particles in the particles in the population (volume distribution) have a diameter less than 10 microns. By way of further example, in such embodiments less than 1 % of the particles in the particles in the population (volume distribution) have a diameter less than 10 microns. In all embodiments, the particle size may be measured using the protocol set out in the abbreviations and definitions section (above).

[0179] To minimize Gl side effects in patients that are often related to a large volume polymer gel moving through the Gl tract, a low Swelling Ratio of thenonabsorbable composition is preferred (0.5 to 10 times its own weight in water). For example, in one such embodiment the nonabsorbable composition has a Swelling Ratio of less than 9. By way of further example, in one such embodiment the nonabsorbable composition has a Swelling Ratio of less than 8. By way of further example, in one such embodiment the nonabsorbable composition has a Swelling Ratio of less than 7. By way of further example, in one such embodiment the nonabsorbable composition has a Swelling Ratio of less than 6. By way of further example, in one such embodiment the nonabsorbable composition has a Swelling Ratio of less than 5. By way of further example, in one such embodiment the nonabsorbable composition has a Swelling Ratio of less than 4. By way of further example, in one such embodiment the nonabsorbablecomposition has a Swelling Ratio of less than 3. By way of further example, in one such embodiment the nonabsorbable composition has a Swelling Ratio of less than 2.

[0180] The amount of the target species (proton, conjugate base of a strong acid and / or strong acid) that is bound as the nonabsorbable composition transits the Gl tract is largely a function of the binding capacity of the composition for the target species (protons, the conjugate base of a strong acid, and / or a strong acid) and the quantity of the nonabsorbable composition administered per day as a daily dose. In general, the theoretical binding capacity for a target species may be determined using a SGF assay and determining the amount of a species that appeared in or disappeared from the SGF buffer during the SGF assay. For example, the theoretical proton binding capacity of a cation exchange resin may be determined by measuring the increase in the amount of cations (other than protons) in the buffer during a SGF assay. Similarly, the theoretical anion binding capacity of an anion exchange resin (in a form other than the chloride form) may be determined by measuring the increase in the amount of anions (other than chloride ions) in the buffer during a SGF assay. Additionally, the theoretical anion binding capacity of a neutral composition for protons and the conjugate base of a strong acid may be determined by measuring the decrease in chloride concentration in the buffer during a SGF assay.

[0181] In general, the nonabsorbable composition will have a theoretical binding capacity for the target species of at least about 0.5 mEq / g (as determined in an SGF assay). For example, in some embodiments the nonabsorbable composition will have a theoretical binding capacity for the target species of at least about 1 mEq / g. By way of further example, in some embodiments the nonabsorbable composition will have a theoretical binding capacity for the target species of at least about 2 mEq / g. By way of further example, in some embodiments the nonabsorbable composition will have a theoretical binding capacity for the target species of at least about 3 mEq / g. By way of further example, in some embodiments the nonabsorbable composition will have a theoretical binding capacity for the target species of at least about 4 mEq / g. By way of further example, in some embodiments the nonabsorbable composition will have a theoretical binding capacity for the target species of at least about 5 mEq / g. By way of further example, in some embodiments the nonabsorbable composition will have a theoretical binding capacity for the target species of at least about 7.5 mEq / g. By way of further example, in some embodiments the nonabsorbable composition will have atheoretical binding capacity for the target species of at least about 10 mEq / g. By way of further example, in some embodiments the nonabsorbable composition will have a theoretical binding capacity for the target species of at least about 12.5 mEq / g. By way of further example, in some embodiments the nonabsorbable composition will have a theoretical binding capacity for the target species of at least about 15 mEq / g. By way of further example, in some embodiments the nonabsorbable composition will have a theoretical binding capacity for the target species of at least about 20 mEq / g. In general, the nonabsorbable composition will typically have a theoretical binding capacity for the target species that is not in excess of about 35 mEq / g. For example, in some embodiments, the theoretical binding capacity of the nonabsorbable compositions for the target species that is not be excess of 30 mEq / g. Thus, for example, the theoretical binding capacity of the nonabsorbable compositions for the target species may range from 2 to 25 mEq / g, 3 to 25 mEq / g, 5 to 25 mEq / g, 10 to 25 mEq / g, 5 to 20 mEq / g, 6 to 20 mEq / g, 7.5 to 20 mEq / g, or even 10 to 20 mEq / g. In those embodiments in which the target species comprises protons and at least one conjugate base, the binding capacities recited in this paragraph are the theoretical binding capacities for protons and the theoretical binding capacities for the conjugate base(s), independently and individually, and not the sum thereof.

[0182] In general, the nonabsorbable composition will have a theoretical binding capacity for protons of at least about 0.5 mEq / g (as determined in an SGF assay). For example, in some embodiments the nonabsorbable composition will have a theoretical binding capacity for protons of at least about 1 mEq / g. By way of further example, in some embodiments the nonabsorbable composition will have a theoretical binding capacity for protons of at least about 2 mEq / g. By way of further example, in some embodiments the nonabsorbable composition will have a theoretical binding capacity for protons of at least about 3 mEq / g. By way of further example, in some embodiments the nonabsorbable composition will have a theoretical binding capacity for protons of at least about 4 mEq / g. By way of further example, in some embodiments the nonabsorbable composition will have a theoretical binding capacity for protons of at least about 5 mEq / g. By way of further example, in some embodiments thenonabsorbable composition will have a theoretical binding capacity for protons of at least about 7.5 mEq / g. By way of further example, in some embodiments thenonabsorbable composition will have a theoretical binding capacity for protons of atleast about 10 mEq / g. By way of further example, in some embodiments the nonabsorbable composition will have a theoretical binding capacity for protons of at least about 12.5 mEq / g. By way of further example, in some embodiments the nonabsorbable composition will have a theoretical binding capacity for protons of at least about 15 mEq / g. By way of further example, in some embodiments thenonabsorbable composition will have a theoretical binding capacity for protons of at least about 20 mEq / g. In general, the nonabsorbable composition will typically have a theoretical binding capacity for protons that is not in excess of about 35 mEq / g. For example, in some embodiments, the theoretical binding capacity of the nonabsorbable compositions for protons that is not be excess of 30 mEq / g. Thus, for example, the theoretical binding capacity of the nonabsorbable compositions for protons may range from 2 to 25 mEq / g, 3 to 25 mEq / g, 5 to 25 mEq / g, 10 to 25 mEq / g, 5 to 20 mEq / g, 6 to 20 mEq / g, 7.5 to 20 mEq / g, or even 10 to 20 mEq / g. In those embodiments in which the target species comprises protons and at least one conjugate base, the binding capacities recited in this paragraph are the theoretical binding capacities for protons and the theoretical binding capacities for the conjugate base(s), independently and individually, and not the sum thereof.

[0183] Phosphate, bicarbonate, bicarbonate equivalents, the conjugate bases of bile and fatty acids are potential interfering anions for chloride or other conjugate bases of strong acids (e.g., HS04"and S042") in the stomach and small intestine.Therefore, rapid and preferential binding of chloride over phosphate, bicarbonate equivalents, and the conjugate bases of bile and fatty acids in the small intestine is desirable and the SIB assay may be used to determine kinetics and preferential binding. Since the transit time of the colon is slow (2-3 days) relative to the small intestine, and since conditions in the colon will not be encountered by an orally administered nonabsorbable composition until after stomach and small intestine conditions have been encountered, kinetics of chloride binding by a nonabsorbable composition do not need to be as rapid in the colon or under in vitro conditions designed to mimic the late small intestine / colon. It is, however, desirable that chloride binding and selectivity over other interfering anions is high, for example, at 24 and / or 48 hours or longer.

[0184] In one embodiment, the nonabsorbable composition is characterized by a chloride ion binding capacity of at least 1 mEq / g in a Simulated Small Intestine Inorganic Buffer ("SIB") assay. For example, in one such embodiment thenonabsorbable composition is characterized by a chloride ion binding capacity of at least 1 .5 mEq / g in a SIB assay. By way of further example, in one such embodiment the nonabsorbable composition is characterized by a chloride ion binding capacity of at least 2 mEq / g in a SIB assay. By way of further example, in one such embodiment the nonabsorbable composition is characterized by a chloride ion binding capacity of at least 2.5 mEq / g in a SIB assay. By way of further example, in one such embodiment the nonabsorbable composition is characterized by a chloride ion binding capacity of at least 3 mEq / g in a SIB assay. By way of further example, in one such embodiment the nonabsorbable composition is characterized by a chloride ion binding capacity of at least 3.5 mEq / g in a SIB assay. By way of further example, in one such embodiment the nonabsorbable composition is characterized by a chloride ion binding capacity of at least 4 mEq / g in a SIB assay. By way of further example, in one such embodiment the nonabsorbable composition is characterized by a chloride ion binding capacity of at least 4.5 mEq / g in a SIB assay. By way of further example, in one such embodiment the nonabsorbable composition is characterized by a chloride ion binding capacity of at least 5 mEq / g in a SIB assay. By way of further example, in one such embodiment the nonabsorbable composition is characterized by a chloride ion binding capacity of at least 5.5 mEq / g in a SIB assay. By way of further example, in one such embodiment the nonabsorbable composition is characterized by a chloride ion binding capacity of at least 6 mEq / g in a SIB assay.

[0185] In one embodiment, the nonabsorbable composition binds a significant amount of chloride relative to phosphate as exhibited, for example, in a SIB assay. For example, in one embodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 0.1 : 1 , respectively. By way of further example, in one such embodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 0.2: 1 , respectively. By way of further example, in one such embodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 0.25: 1 , respectively. By way of further example, in one such embodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 0.3: 1 , respectively. By way of further example, in one suchembodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 0.35: 1 , respectively. By way of further example, in one suchembodiment the ratio of the amount of bound chloride to bound phosphate in a SIBassay is at least 0.4: 1 , respectively. By way of further example, in one such embodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 0.45: 1 , respectively. By way of further example, in one such embodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 0.5: 1 , respectively. By way of further example, in one suchembodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 2:3, respectively. By way of further example, in one such embodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 0.75: 1 , respectively. By way of further example, in one such embodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 0.9:1 , respectively. By way of further example, in one such embodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 1 : 1 ,respectively. By way of further example, in one such embodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 1 .25: 1 , respectively. By way of further example, in one such embodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 1 .5: 1 , respectively. By way of further example, in one such embodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 1 .75: 1 , respectively. By way of further example, in one such embodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 2: 1 ,respectively. By way of further example, in one such embodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 2.25: 1 , respectively. By way of further example, in one such embodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 2.5: 1 , respectively. By way of further example, in one such embodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 2.75: 1 , respectively. By way of further example, in one such embodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 3: 1 ,respectively. By way of further example, in one such embodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 4: 1 ,respectively. By way of further example, in one such embodiment the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 5: 1 ,respectively.

[0186] In one embodiment, the orally administered nonabsorbable composition is characterized by a proton-binding capacity and a chloride binding capacity in Simulated Gastric Fluid of at least 1 mEq / g in a SGF assay. For example, in one such embodiment the nonabsorbable composition is characterized by a proton- binding capacity and a chloride binding capacity in a SGF assay of at least 2 mEq / g. By way of further example, in one such embodiment the nonabsorbable composition is characterized by a proton-binding capacity and a chloride binding capacity in a SGF assay of at least 3 mEq / g. By way of further example, in one such embodiment the nonabsorbable composition is characterized by a proton-binding capacity and a chloride binding capacity in a SGF assay of at least 4 mEq / g. By way of further example, in one such embodiment the nonabsorbable composition is characterized by a proton-binding capacity and a chloride binding capacity in a SGF assay of at least 5 mEq / g. By way of further example, in one such embodiment the nonabsorbable composition ischaracterized by a proton-binding capacity and a chloride binding capacity in a SGF assay of at least 6 mEq / g. By way of further example, in one such embodiment the nonabsorbable composition is characterized by a proton-binding capacity and a chloride binding capacity in a SGF assay of at least 7 mEq / g. By way of further example, in one such embodiment the nonabsorbable composition is characterized by a proton-binding capacity and a chloride binding capacity in a SGF assay of at least 8 mEq / g. By way of further example, in one such embodiment the nonabsorbable composition ischaracterized by a proton-binding capacity and a chloride binding capacity in a SGF assay of at least 9 mEq / g. By way of further example, in one such embodiment the nonabsorbable composition is characterized by a proton-binding capacity and a chloride binding capacity in a SGF assay of at least 10 mEq / g. By way of further example, in one such embodiment the nonabsorbable composition is characterized by a proton- binding capacity and a chloride binding capacity in a SGF assay of at least 1 1 mEq / g. By way of further example, in one such embodiment the nonabsorbable composition is characterized by a proton-binding capacity and a chloride binding capacity in a SGF assay of at least 12 mEq / g. By way of further example, in one such embodiment the nonabsorbable composition is characterized by a proton-binding capacity and a chloride binding capacity in a SGF assay of at least 13 mEq / g. By way of further example, in one such embodiment the nonabsorbable composition is characterized by a proton- binding capacity and a chloride binding capacity in a SGF assay of at least 14 mEq / g.By way of further example, in one such embodiment the nonabsorbable composition ischaracterized by a proton-binding capacity and a chloride binding capacity after 1 hour in SGF that is at least 50% of the proton-binding capacity and the chloride binding capacity, respectively, of the nonabsorbable composition at 24 hours in SGF. By way of further example, in one such embodiment the nonabsorbable composition ischaracterized by a proton-binding capacity and a chloride binding capacity after 1 hour in SGF that is at least 60% of the proton-binding capacity and the chloride binding capacity, respectively, of the nonabsorbable composition at 24 hours in SGF. By way of further example, in one such embodiment the nonabsorbable composition ischaracterized by a proton-binding capacity and a chloride binding capacity after 1 hour in SGF that is at least 70% of the proton-binding capacity and the chloride binding capacity, respectively, of the nonabsorbable composition at 24 hours in SGF. By way of further example, in one such embodiment the nonabsorbable composition ischaracterized by a proton-binding capacity and a chloride binding capacity after 1 hour in SGF that is at least 80% of the proton-binding capacity and the chloride binding capacity, respectively, of the nonabsorbable composition at 24 hours in SGF. By way of further example, in one such embodiment the nonabsorbable composition ischaracterized by a proton-binding capacity and a chloride binding capacity after 1 hour in SGF that is at least 90% of the proton-binding capacity and the chloride binding capacity, respectively, of the nonabsorbable composition at 24 hours in SGF.

[0187] In one embodiment, the nonabsorbable composition is a cation exchange material comprising an insoluble (in the gastric environment) support structure and exchangeable cations. The cation exchange material may be organic (e.g., polymeric), inorganic (e.g. , a zeolite) or a composite thereof. The exchangeable cations may be selected, for example, from the group consisting of lithium, sodium, potassium, calcium, magnesium, iron and combinations thereof, and more preferably from the group consisting of sodium, potassium, calcium, magnesium, andcombinations thereof. In such embodiments it is generally preferred that thenonabsorbable composition contain a combination of exchangeable cations that establish or maintain electrolyte homeostasis. For example, in one such embodiment the nonabsorbable composition optionally contains exchangeable sodium ions, but when included, the amount of the sodium ions in a daily dose is insufficient to increase the patient's serum sodium ion concentration to a value outside the range of 135 to 145 mEq / l. By way of further example, in one such embodiment the nonabsorbablecomposition optionally contains exchangeable potassium ions, but when included, the amount of the potassium ions in a daily dose is insufficient to increase the patient's serum potassium ion concentration to a value outside the range of 3.7 to 5.2 mEq / L. By way of further example, in one such embodiment the nonabsorbable composition optionally contains exchangeable magnesium ions, but when included, the amount of the magnesium ions in a daily dose is insufficient to increase the patient's serum magnesium ion concentration to a value outside the range of 1 .7 to 2.2 mg / dL. By way of further example, in one such embodiment the nonabsorbable composition optionally contains exchangeable calcium ions, but when included, the amount of the calcium ions in a daily dose is insufficient to increase the patient's serum calcium ion concentration to a value outside the range of 8.5 to 10.2 mg / dL. By way of further example, in one such embodiment the nonabsorbable composition contains a combination of exchangeable cations selected from the group consisting of sodium, potassium, calcium, magnesium, and combinations thereof, designed to maintain serum Na+levels within the range of 135 to 145 mEq / l, serum K+levels within the range of 3.7 to 5.2 mEq / L, serum Mg2+levels within the range of 1 .7 to 2.2 mg / dL and serum Ca2+levels within the range of 8.5 to 10.2 mg / dL.

[0188] In one embodiment, the nonabsorbable composition is a cation exchange material comprising an insoluble (in the gastric environment) support structure, optionally containing exchangeable sodium ions cations. The cation exchange material may be organic (e.g., polymeric), inorganic (e.g., a molecular sieve) or a composite thereof. In one such embodiment, the nonabsorbable composition contains less than 12% by weight sodium. For example, in one such embodiment the nonabsorbable composition contains less than 9% by weight sodium. By way of further example, in one such embodiment the nonabsorbable composition contains less than 6% by weight sodium. By way of further example, in one such embodiment the nonabsorbable composition contains less than 3% by weight sodium. By way of further example, in one such embodiment the nonabsorbable composition contains less than 1 % by weight sodium. By way of further example, in one such embodiment the nonabsorbable composition contains less than 0.1 % by weight sodium. By way of further example, in one such embodiment the nonabsorbable composition contains less than 0.01 % by weight sodium. By way of further example, in one such embodiment the nonabsorbable composition contains between 0.05 and 3% by weight sodium.

[0189] In one exemplary embodiment, the nonabsorbable composition is a resin comprising any of a wide range of crosslinked polymeric materials that are able to bind protons in aqueous solutions. Exemplary crosslinked polymeric material comprises a polyanion crosslinked material selected from poly(carboxylic acids), poly(acrylic acids), poly(sulfonic acids), poly(maleic acids), poly(phenols), functionalized polyols and poly(alcohols), poly(hydroxamic acids), poly(imides) and copolymers thereof. In one embodiment, the polyanion is coordinated to exchangeable monovalent cations, divalent cations, or a combination thereof. Exemplary monovalent cations include lithium, sodium, and potassium, or any combination thereof. Exemplary divalent cations include magnesium and calcium or combinations thereof.

[0190] In one exemplary embodiment, the nonabsorbable composition is a cation exchange resin comprising a polyanion backbone that exchanges cations for protons and has an average pKa of at least 4. For example, in one embodiment, the polyanion backbone has an average pKa of 4-5. By way of further example, in one such embodiment the polyanion backbone has an average pKa of 5-6. By way of further example, in one such embodiment the polyanion backbone has an average pKa of 6-7. By way of further example, in one such embodiment the polyanion backbone has an average pKa of greater than 7. Exemplary cation exchange resins include poly(carboxylic acids), poly(acrylic acids), poly(sulfonic acids), poly(maleic acids), poly(phenols), functionalized polyols and poly(alcohols), poly(hydroxamic acids), poly(imides) and copolymers thereof. In one embodiment, these polyanion backbones are further functionalized with functional groups to affect the pKa. These functional groups can increase pKa when electron donating, or decrease pKa when electron withdrawing. Exemplary electron donating groups include amino, hydroxyl, methyl ether, ether, phenyl, and amido. Exemplary electron withdrawing groups include flouro, chloro, halo, sulphonyl, nitroxyl, trifluoromethyl, and cyano. Further exemplary cation exchange resins include resins modified with protonable functional groups including carboxylic acids and functionalized alcohols.

[0191] Polymeric cation exchanger resins may be prepared using a range of chemistries, including for example, (i) substitution polymerization of polyfunctional reagents at least one of which comprises basic anionic or conjugate-acid moieties, (2) radical polymerization of a monomer comprising at least one acid or conjugate-acid containing moiety, and (3) crosslinking of a basic anionic or conjugate-acid containingintermediate with a polyfunctional crosslinker, optionally containing basic anionic or conjugate-acid moieties. The resulting crosslinked polymers may thus, for example, be crosslinked homopolymers or crosslinked copolymers. By way of further example, the resulting crosslinked polymers will typically possess repeat units comprising basic anionic or conjugate-acid, separated by the same or varying lengths of repeating linker (or intervening) units. In some embodiments, the polymers comprise repeat units comprising a basic anionic or conjugate-acid moiety and an intervening linker unit. In other embodiments, multiple basic anionic or conjugate-acid containing repeat units are separated by one or more linker units. Additionally, the polyfunctional crosslinkers may comprise proton binding functional groups, e.g. basic anionic, ("active crosslinkers") or may lack proton binding functional groups such as acrylates ("passive crosslinkers").

[0192] In some embodiments, a basic anion or conjugate-acid monomer is polymerized and the polymer is concurrently crosslinked in a substitution polymerization reaction. The basic anion or conjugate-acid reactant (monomer) in the concurrent polymerization and crosslinking reaction can react more than one time for the substitution polymerization. In one such embodiment, the basic anion or conjugate-acid monomer is a branched basic anion or conjugate-acid possessing at least two reactive moieties to participate in the substitution polymerization reaction.

[0193] In one embodiment, the nonabsorbable composition comprises a cation exchange ceramic material. Porous inorganic binders exhibit a range of properties. Functionally, they are able to sequester materials on the basis of their size and polarity, as they exhibit a framework charge with porous structure. They are structurally diverse and can be crystalline or non-crystalline crystalline (amorphous). Classes of porous materials that fall under the class of inorganic binders include hydrous oxides (e.g., aluminum oxide) and metal alumino-silicate compounds where the metal can be an alkali or alkali earth metal such sodium, potassium, lithium, magnesium or calcium. Many of these compounds have well-defined crystalline structures. This class of compounds has been used for various biopharmaceutical applications.

[0194] The pore diameters of inorganic microporous and mesoporous materials are measured in angstroms (A) or nanometers (nm). According to lUPAC notation, microporous materials have pore diameters of less than 2 nm (20 A) and macroporous materials have pore diameters of greater than 50 nm (500 A); the mesoporous category thus lies in the middle with pore diameters between 2 and 50 nm(20-500 A). The porosity of inorganic porous materials can be tuned or designed, by the appropriate use of poragen or "co-monomer metals" within the lattices of the porous material. By the appropriate choice of elements, the pore size has been seen to range in size from 3 A to 8 A. These compositions have a porous system allowing solute together with other dissolved species to enter the porous framework of the material, resulting in absorption of the the dissolved species. Tuning the cavities and pore size of the materials, can allow adsorption of molecules of particular dimensions, while rejecting those of larger dimensions. From a binding perspective using size as a selectivity mechanism the chloride ion has the advantage of its small size (the radius of chloride anion is 1 .8 A, and the molecular weight of chloride anion is 35.5) compared to the other species present in the digestive tract.

[0195] Exemplary cation exchange ceramic materials include any of a wide range of microporous or mesoporous ceramic materials. In one embodiment, the nonabsorbable composition comprises a molecular sieve, such as a molecular sieve selected from the group consisting of silica, titanosilicate, metalloaluminate,aluminophosphate and gallogerminate molecular sieves. In one embodiment, the nonabsorbable composition comprises a zeolite, a borosilicate, a gallosilicate, a ferrisilicate or a chromosilicate molecular sieve.

[0196] Inorganic porous materials exhibit the property of sequestering substances from an external environment. The mechanism to bind proton or chloride or HCI can be either an adsorptive or absorptive mechanism, where the ions are bound via the specific porosity of the matrix, or an ion exchange mechanism. The strongadsorptive force in zeolite molecular sieves are due to the polarity of the surface(hydroxyl metalloid) and cations that are exposed within the crystal lattice. The cations on the surface act as a site of strong localized positive charge that electrostatically attract the partial negative charges of polar molecules (for example, the chloride of HCI). A basic formula for zeolite can be represented by, M2nO.Al203.xSi02.yH20 where M is acation of n valence. The fundamental building block of the molecular sieve structure is tetrahedral with 4 oxygen anions surrounding a silicon or alumina cation. Sodium ions or other cations (e.g. potassium, calcium) make up the positive charge deficit of the alumina tetrahedron to extend the crystal lattice. In many molecular sieve types the sodium can be exchanged or the sodium can function as a permanent positive charge within the crystal lattice thus providing the electrostatic interaction. Given these mechanisms, hydrochloric acid can be sequestered from solution via a cation exchange mechanism (sodium for proton), anion exchange mechanism (hydroxide for chloride), or via electrostatic interaction of the hydrochloric acid ionic species.

[0197] The methods used to bind HCI are well known in the art and involve contacting the molecular sieve with a solution containing the desired HCI concentration in water. Exchange conditions include a temperature of about 25 °C to about 100 °C, and a time of about 20 minutes to about 2 hours. These conditions include conditions and exposure times encountered in the gastrointestinal tract.

[0198] In one embodiment, the nonabsorbable composition is an anion exchange material comprising an insoluble (in the gastric environment) support structure and exchangeable anions. The anion exchange material may be organic (e.g., polymeric), inorganic (e.g., an apatite, hydrotalcite or a hydrated gel of aluminum, iron(lll) or zirconium hydroxide) or a composite thereof.

[0199] In one embodiment, the nonabsorbable composition comprises an anion exchange material. Exemplary anion exchange materials include strongly and weakly basic anion exchange materials. For example, the anion exchange material may include any of a wide range of polymers comprising quaternary amine moieties, phosphonium salts, N-heteroaromatic salts, or combinations thereof. Other exemplary anion exchange materials include poly(ionic liquids), wherein the side chain is selected from the group consisting of salts of tetraalkyl ammonium, imidazolium, pyridinium, pyrrolidonium, guanidinium, piperidinium, and tetraalkyl phosphonium cations and combinations thereof. By way of further example, in one such embodiment the anion exchange material is a halide responsive polymer such that a conformational change occurs when about 1 mEq / g to about 35 mEq / g of chloride is initially bound to the polymer and subsequently retained for the duration of the Gl transit time. In certain embodiments, the halide response conformational change occurs when 2 mEq / g to about 25 mEq / g chloride is bound, and in certain more specific embodiments, the halideresponse conformational change occurs when 3 to 25 mEq / g, 5 to 25 mEq / g, 10 to 25 mEq / g, 5 to 20 mEq / g, 6 to 20 mEq / g, 7.5 to 20 mEq / g, or even 10 to 20 mEq / g chloride is bound. The polymeric backbone of any of the aforementioned polymers can derive from vinyl, allyl, styrenic, acrylamide, meth(acrylamide), or copolymers thereof. By way of further example, the anion exchange functionality may be incorporated into the backbone of the polymer. Examples include poly(tetraalkyl ammonium),poly(imidazolium), poly(pyridinium), poly(pyrrolidonium), poly(piperidinium), and poly(tetraalkyl phosphonium) cations or combinations thereof. The exchangeable anion can consist of hydroxide, bicarbonate, acetate, nitrate or any pharmaceutically and biologically acceptable base or combination thereof.

[0200] In one embodiment, the nonabsorbable composition is an anion exchange material comprising at least 1 mEq / g of an anion selected from the group consisting of hydroxide, carbonate, citrate or other bicarbonate equivalent anion, or a combination thereof. In this embodiment, the nonabsorbable composition has the capacity to induce an increase in the individual's serum bicarbonate value, at least in part, by delivering a physiologically significant amount of hydroxide, carbonate, citrate or other bicarbonate equivalent, or a combination thereof. Exemplary bicarbonate equivalent anions include acetate, lactate and the conjugate bases of other short chain carboxylic acids. In one such embodiment, the nonabsorbable composition comprises at least 2 mEq / g of an anion selected from the group consisting of hydroxide, carbonate, citrate or other bicarbonate equivalent anion. By way of further example, in one such embodiment the nonabsorbable composition comprises at least 3 mEq / g of an anion selected from the group consisting of hydroxide, carbonate, citrate or other bicarbonate equivalent anion. By way of further example, in one such embodiment thenonabsorbable composition comprises at least 4 mEq / g of an anion selected from the group consisting of hydroxide, carbonate, citrate or other bicarbonate equivalent anion. By way of further example, in one such embodiment the nonabsorbable composition comprises at least 5 mEq / g of an anion selected from the group consisting of hydroxide, carbonate, citrate or other bicarbonate equivalent anion.

[0201] In one embodiment, the nonabsorbable composition is an anion exchange material comprising less than 10 mEq / g of an anion selected from the group consisting of hydroxide, carbonate, citrate or other bicarbonate equivalent anion, or a combination thereof. In one such embodiment, the nonabsorbable compositioncomprises less than 7.5 mEq / g of an anion selected from the group consisting of hydroxide, carbonate, citrate or other bicarbonate equivalent anion. By way of further example, in one such embodiment the nonabsorbable composition comprises less than 5 mEq / g of an anion selected from the group consisting of hydroxide, carbonate, citrate or other bicarbonate equivalent anion. By way of further example, in one such embodiment the nonabsorbable composition comprises less than 2.5 mEq / g of an anion selected from the group consisting of hydroxide, carbonate, citrate or other bicarbonate equivalent anion. By way of further example, in one such embodiment thenonabsorbable composition comprises less than 1 mEq / g of an anion selected from the group consisting of hydroxide, carbonate, citrate or other bicarbonate equivalent anion. By way of further example, in one such embodiment the nonabsorbable composition comprises less than 0.1 mEq / g of an anion selected from the group consisting of hydroxide, carbonate, citrate or other bicarbonate equivalent anion.

[0202] In one embodiment, the nonabsorbable composition comprises an amphoteric ion exchange resin. Exemplary amphoteric ion-exchange resins include crosslinked polystyrene, polyethylene or the like as a base material and quaternary ammonium group, carboxylic acid group and the like in (i) the same pendant groups (e.g., betaine-containing pendant groups) such as the amphoteric resin sold under the trade designation DIAION AMP03 (Mitsubishi Chemical Corporation) or (ii) different pendant groups (e.g., mixed charged copolymers containing the residues of at least two different monomers, one containing ammonium groups and one containing carboxylic acid groups), to provide a function of ion-exchanging the both of cations and negative ions. Exemplary amphoteric ion-exchange resins containing a mixture of cation and anion exchange sites also include resins in which a linear polymer is trapped inside a crosslinked ion exchange resin, such as the amphoteric resin sold under the trade designation DOWEX™ Retardion 1 1A8 (Dow Chemical Company).

[0203] In one embodiment, the nonabsorbable composition comprises a neutral composition having the capacity to bind both protons and anions. Exemplary neutral nonabsorbable compositions that bind both protons and anions include polymers functionalized with propylene oxide, polymers functional ized with Michael acceptors, expanded porphyrins, covalent organic frameworks, and polymers containing amine and / or phosphine functional groups.

[0204] In those embodiments in which the nonabsorbable composition binds chloride ions, it is generally preferred that the nonabsorbable composition selectively bind chloride ions relative to other counter ions such as bicarbonate equivalent anions, phosphate anions, and the conjugate bases of bile and fatty acids. Stated differently, it is generally preferred in these embodiments that the nonabsorbable composition (i) remove more chloride ions than bicarbonate equivalent anions (ii) remove more chloride ions than phosphate anions, and (iii) remove more chloride ions than the conjugate bases of bile and fatty acids. Advantageously, therefore, treatment with thenonabsorbable composition does not induce or exacerbate hypophosphatemia (i.e., a serum phosphorous concentration of less than about 2.4 mg / dL, does not significantly elevate low density lipoproteins ("LDL"), or otherwise negatively impact serum or colon levels of metabolically relevant anions.

[0205] In some embodiments, the pharmaceutical composition comprises a crosslinked polymer containing the residue of an amine corresponding to Formula 1 :N IR3Formula 1 wherein R-i , R2and R3are independently hydrogen, hydrocarbyl, substitutedhydrocarbyl provided, however, at least one of R-i , R2and R3is other than hydrogen. Stated differently, at least one of R-i , R2and R3is hydrocarbyl or substitutedhydrocarbyl, and the others of R-i , R2and R3are independently hydrogen, hydrocarbyl, or substituted hydrocarbyl. In one embodiment, for example, R-i , R2and R3are independently hydrogen, aryl, aliphatic, heteroaryl, or heteroaliphatic provided, however, each of R-i , R2and R3are not hydrogen. By way of further example, in one such embodiment R-i , R2and R3are independently hydrogen, saturated hydrocarbons, unsaturated aliphatic, unsaturated heteroaliphatic, heteroalkyl, heterocyclic, aryl or heteroaryl, provided, however, each of R-i , R2and R3are not hydrogen. By way of further example, in one such embodiment R-i , R2and R3are independently hydrogen, alkyl, alkenyl, allyl, vinyl, aryl, aminoalkyl, alkanol, haloalkyl, hydroxyalkyl, ethereal, heteroaryl or heterocyclic provided, however, each of R-i , R2and R3are not hydrogen. By way of further example, in one such embodiment R-i , R2and R3are independently hydrogen, alkyl, aminoalkyl, alkanol, aryl, haloalkyl, hydroxyalkyl, ethereal, heteroaryl orheterocyclic provided, however, each of R-i, R2and R3are not hydrogen. By way of further example, in one such embodiment Ri and R2(in combination with the nitrogen atom to which they are attached) together constitute part of a ring structure, so that the monomer as described by Formula 1 is a nitrogen-containing heterocycle (e.g., piperidine) and R3is hydrogen, or heteroaliphatic. By way of further example, in one embodiment R-i, R2and R3are independently hydrogen, aliphatic or heteroaliphatic provided, however, at least one of R-i , R2and R3is other than hydrogen. By way of further example, in one embodiment R-i, R2and R3are independently hydrogen, allyl, or aminoalkyl.

[0206] In one embodiment, the crosslinked polymer comprises the residue of an amine corresponding to Formula 1 wherein R-i , R2, and R3are independently hydrogen, heteroaryl, aryl, aliphatic or heteroaliphatic provided, however, at least one of R-i, R2, and R3is aryl or heteroaryl. For example, in this embodiment Ri and R2, in combination with the nitrogen atom to which they are attached, may form a saturated or unsaturated nitrogen-containing heterocyclic ring. By way of further example, R-i and R2, in combination with the nitrogen atom to which they are attached may constitute part of a pyrrolidino, pyrole, pyrazolidine, pyrazole, imidazolidine, imidazole, piperidine, pyridine, piperazine, diazine, or triazine ring structure. By way of further example, Ri and R2, in combination with the nitrogen atom to which they are attached may constitute part of a piperidine ring structure.

[0207] In one embodiment, the crosslinked polymer comprises the residue of an amine corresponding to Formula 1 wherein R-i , R2, and R3are independently hydrogen, aliphatic, or heteroaliphatic provided, however, at least one of R-i , R2, and R3is other than hydrogen. For example, in this embodiment R-i , R2, and R3mayindependently be hydrogen, alkyl, alkenyl, allyl, vinyl, aminoalkyl, alkanol, haloalkyl, hydroxyalkyl, ethereal, or heterocyclic provided, however, at least one of R-i, R2, and R3is other than hydrogen. By way of further example, in one such embodiment R-i and R2, in combination with the nitrogen atom to which they are attached, may form a saturated or unsaturated nitrogen-containing heterocyclic ring. By way of further example, in one such embodiment Ri and R2, in combination with the nitrogen atom to which they are attached may constitute part of a pyrrolidino, pyrole, pyrazolidine, pyrazole,imidazolidine, imidazole, piperidine, piperazine, or diazine ring structure. By way of further example, in one such embodiment Ri and R2, in combination with the nitrogenatom to which they are attached may constitute part of a piperidine ring structure. By way of further example, in one such embodiment the amine corresponding to Formula 1 is acyclic and at least one of R-i , R2, and R3is aliphatic or heteroaliphatic. By way of further example, in one such embodiment R-i , R2, and R3are independently hydrogen, alkyl, allyl, vinyl, alicyclic, aminoalkyl, alkanol, or heterocyclic, provided at least one of R-i , R2, and R3is other than hydrogen.

[0208] In one embodiment, the crosslinked polymer comprises the residue of an amine corresponding to Formula 1 and the crosslinked polymer is prepared by substitution polymerization of the amine corresponding to Formula 1 with apolyfunctional crosslinker (optionally also comprising amine moieties) wherein R-i , R2, and R3are independently hydrogen, alkyl, aminoalkyl, or alkanol, provided at least one of R-i , R2, and R3is other than hydrogen.

[0209] In some embodiments, the molecular weight per nitrogen of the polymers of the present disclosure may range from about 40 to about 1000 Daltons. In one embodiment, the molecular weight per nitrogen of the polymer is from about 40 to about 500 Daltons. In another embodiment, the molecular weight per nitrogen of the polymer is from about 50 to about 170 Daltons. In another embodiment, the molecular weight per nitrogen of the polymer is from about 60 to about 1 10 Daltons.

[0210] In some embodiments, an amine-containing monomer is polymerized and the polymer is concurrently crosslinked in a substitution polymerization reaction in the first reaction step. The amine reactant (monomer) in the concurrent polymerization and crosslinking reaction can react more than one time for the substitutionpolymerization. In one such embodiment, the amine monomer is a linear amine possessing at least two reactive amine moieties to participate in the substitution polymerization reaction. In another embodiment, the amine monomer is a branched amine possessing at least two reactive amine moieties to participate in the substitution polymerization reaction. Crosslinkers for the concurrent substitution polymerization and crosslinking typically have at least two amine-reactive moieties such as alkyl-chlorides, and alkyl-epoxides. In order to be incorporated into the polymer, primary amines react at least once and potentially may react up to three times with the crosslinker, secondary amines can react up to twice with the crosslinkers, and tertiary amines can only react once with the crosslinker. In general, however, the formation of a significant number ofquaternary nitrogens / amines is generally not preferred because quaternary amines cannot bind protons.

[0211] Exemplary amines that may be used in substitution polymerization reactions described herein include 1 ,3-Bis[bis(2-aminoethyl)amino]propane, 3-Amino-1 - {[2-(bis{2-[bis(3-aminopropyl)amino]ethyl}amino)ethyl](3-aminopropyl)amino}propane, 2- [Bis(2-aminoethyl)amino]ethanamine, Tris(3-aminopropyl)amine, 1 ,4-Bis[bis(3- aminopropyl)amino]butane, 1 ,2-Ethanediamine, 2-Amino-1 -(2-aminoethylamino)ethane, 1 ,2-Bis(2-aminoethylamino)ethane, 1 ,3-Propanediamine, 3,3'-Diaminodipropylamine,2.2- dimethyl-1 ,3-propanediamine, 2-methyl-1 ,3-propanediamine, N,N'-dimethyl-1 ,3- propanediamine, N-methyl-1 ,3-diaminopropane, 3,3'-diamino-N-methyldipropylamine,1.3- diaminopentane, 1 ,2-diamino-2-methylpropane, 2-methyl-1 ,5-diaminopentane, 1 ,2- diaminopropane, 1 ,10-diaminodecane, 1 ,8-diaminooctane, 1 ,9-diaminooctane, 1 ,7- diaminoheptane, 1 ,6-diaminohexane, 1 ,5-diaminopentane, 3-bromopropylamine hydrobromide, N,2-dimethyl-1 ,3-propanediamine, N-isopropyl-1 ,3-diaminopropane, N,N'-bis(2-aminoethyl)-1 ,3-propanediamine, N,N'-bis(3-aminopropyl)ethylenediamine, N,N'-bis(3-aminopropyl)-1 ,4-butanediamine tetrahydrochloride, 1 ,3-diamino-2-propanol, N-ethylethylenediamine, 2,2'-diamino-N-methyldiethylamine, Ν,Ν'- diethylethylenediamine, N-isopropylethylenediamine, N-methylethylenediamine, N,N'-di- tert-butylethylenediamine, Ν,Ν'-diisopropylethylenediamine, Ν,Ν'- dimethylethylenediamine, N-butylethylenediamine, 2-(2-aminoethylamino)ethanol,1 ,4,7, 10, 13, 16-hexaazacyclooctadecane, 1 ,4,7,10-tetraazacyclododecane, 1 ,4,7- triazacyclononane, N,N'-bis(2-hydroxyethyl)ethylenediamine, piperazine,bis(hexamethylene)triamine, N-(3-hydroxypropyl)ethylenediamine, N-(2- Aminoethyl)piperazine, 2-Methylpiperazine, Homopiperazine, 1 ,4,8, 1 1 - Tetraazacyclotetradecane, 1 ,4,8, 12-Tetraazacyclopentadecane, 2- (Aminomethyl)piperidine, 3-(Methylamino)pyrrolidine

[0212] Exemplary crosslinking agents that may be used in substitution polymerization reactions and post-polymerization crosslinking reactions include, but are not limited to, one or more multifunctional crosslinking agents such as: dihaloalkanes, haloalkyloxiranes, alkyloxirane sulfonates, di(haloalkyl)amines, tri(haloalkyl) amines, diepoxides, triepoxides, tetraepoxides, bis (halomethyl)benzenes,tri(halomethyl)benzenes, tetra(halomethyl)benzenes, epihalohydrins such asepichlorohydrin and epibromohydrin poly(epichlorohydrin), (iodomethyl)oxirane, glycidyltosylate, glycidyl 3-nitrobenzenesulfonate, 4-tosyloxy-1 ,2-epoxybutane, bromo-1 ,2- epoxybutane, 1 ,2-dibromoethane, 1 ,3-dichloropropane, 1 ,2- dichloroethane, l-bromo-2- chloroethane, 1 ,3- dibromopropane, bis(2-chloroethyl)amine, tris(2- chloroethyl)amine, and bis(2-chloroethyl)methylamine, 1 ,3-butadiene diepoxide, 1 ,5-hexadiene diepoxide, diglycidyl ether, 1 ,2,7,8-diepoxyoctane, 1 ,2,9, 10-diepoxydecane, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1 ,4-butanediol diglycidyl ether, 1 ,2 ethanedioldiglycidyl ether, glycerol diglycidyl ether, 1 ,3-diglycidyl glyceryl ether, N,N- diglycidylaniline, neopentyl glycol diglycidyl ether, diethylene glycol diglycidyl ether, 1 ,4- bis(glycidyloxy)benzene, resorcinol digylcidyl ether, 1 ,6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, 1 ,4-cyclohexanedimethanol diglycidyl ether, 1 ,3-bis- (2,3-epoxypropyloxy)-2-(2,3-dihydroxypropy loxy )propane, 1 ,2-cyclohexanedicarboxylic acid diglycidyl ester, 2,2'-bis(glycidyloxy) diphenylmethane, bisphenol F diglycidyl ether, 1 ,4-bis(2',3'epoxypropyl )perfluoro-n-butane, 2,6-di(oxiran-2-ylmethy1 )- 1 ,2,3,5,6,7- hexahydropyrrolo[3,4-f]isoindol-1 ,3,5,7- tetraone, bisphenol A diglycidyl ether, ethyl 5- hydroxy-6,8- di(oxiran-2-ylmethyl)-4-oxo-4-h-chromene-2-carboxylate, bis[4-(2,3-epoxy- propylthio )phenyl]-sulfide, 1 ,3-bis(3-glycidoxypropyl) tetramethyldisiloxane, 9,9-bis[4- (glycidyloxy)phenyl]fluorine, triepoxyisocyanurate, glycerol triglycidyl ether, N,N- diglycidyl-4-glycidyloxyaniline, isocyanuric acid (S,S,S)-triglycidyl ester, isocyanuric acid (R,R,R)-triglycidyl ester, triglycidyl isocyanurate, trimethylolpropane triglycidyl ether, glycerol propoxylate triglycidyl ether, triphenylolmethane triglycidyl ether, 3,7, 14-tris[[3- (epoxypropoxy )propyl]dimethylsilyloxy ]-1 ,3,5,7,9, 1 1 , 14- heptacyclopentyltricyclo[7,3,3,15, 1 1 ]heptasiloxane, 4,4 'methylenebis(N,N-diglycidylaniline),bis(halomethyl)benzene, bis(halomethyl)biphenyl and bis(halomethyl)naphthalene, toluene diisocyanate, acrylol chloride, methyl acrylate, ethylene bisacrylamide, pyrometallic dianhydride, succinyl dichloride, dimethylsuccinate, 3-chloro-1 -(3- chloropropylamino-2-propanol, 1 ,2-bis(3-chloropropylamino)ethane, Bis(3- chloropropyl)amine, 1 ,3-Dichloro-2-propanol, 1 ,3-Dichloropropane, 1 -chloro-2,3- epoxypropane, tris[(2-oxiranyl)methyl]amine.

[0213] In some embodiments, the carbon to nitrogen ratio of the polymers of the present disclosure may range from about 2: 1 to about 6:1 , respectively. For example, in one such embodiment, the carbon to nitrogen ratio of the polymers of the present disclosure may range from about 2.5: 1 to about 5: 1 , respectively. By way of further example, in one such embodiment, the carbon to nitrogen ratio of the polymersof the present disclosure may range from about 3: 1 to about 4.5: 1 , respectively. By way of further example, in one such embodiment, the carbon to nitrogen ratio of the polymers of the present disclosure may range from about 3.25: 1 to about 4.25: 1 , respectively. By way of further example, in one such embodiment, the carbon to nitrogen ratio of the polymers of the present disclosure may range from about 3.4: 1 to about 4: 1 , respectively. In another embodiment, the molecular weight per nitrogen of the polymer is from about 60 to about 1 10 Daltons.

[0214] In some embodiments, the crosslinked polymer comprises the residue of an amine corresponding to Formula 1 a and the crosslinked polymer is prepared by radical polymerization of an amine corresponding to Formula 1 a:R4— CH2CH=CH2NR5Formula 1 a wherein R4and R5are independently hydrogen, hydrocarbyl, or substituted hydrocarbyl. In one embodiment, for example, R4and R5are independently hydrogen, saturated hydrocarbon, unsaturated aliphatic, aryl, heteroaryl, unsaturated heteroaliphatic, heterocyclic, or heteroalkyl. By way of further example, in one such embodiment R4and R5are independently hydrogen, aliphatic, heteroaliphatic, aryl, or heteroaryl. By way of further example, in one such embodiment R4and R5are independently hydrogen, alkyl, alkenyl, allyl, vinyl, aryl, aminoalkyl, alkanol, haloalkyl, hydroxyalkyl, ethereal, heteroaryl or heterocyclic. By way of further example, in one suchembodiment R4and R5are independently hydrogen, alkyl, allyl, aminoalkyl, alkanol, aryl, haloalkyl, hydroxyalkyl, ethereal, or heterocyclic. By way of further example, in one such embodiment R4and R5(in combination with the nitrogen atom to which they are attached) together constitute part of a ring structure, so that the monomer as described by Formula 1 a is a nitrogen-containing heterocycle (e.g. , piperidine). By way of further example, in one embodiment R4and R5are independently hydrogen, aliphatic or heteroaliphatic. By way of further example, in one embodiment R4and R5areindependently hydrogen, allyl, or aminoalkyl.

[0215] In some embodiments, the crosslinked polymer comprises the residue of an amine corresponding to Formula 1 b and the crosslinked polymer is prepared bysubstitution polymerization of the amine corresponding to Formula 1 b with a polyfunctional crosslinker (optionally also comprising amine moieties):Formula 1 b wherein R4and R5are independently hydrogen, hydrocarbyl, or substituted hydrocarbyl, R6is aliphatic and R6i and R62 are independently hydrogen, aliphatic, or heteroaliphatic. In one embodiment, for example, R4and R5are independently hydrogen, saturated hydrocarbon, unsaturated aliphatic, aryl, heteroaryl, heteroalkyl, or unsaturated heteroaliphatic. By way of further example, in one such embodiment R4and R5are independently hydrogen, aliphatic, heteroaliphatic, aryl, or heteroaryl. By way of further example, in one such embodiment R4and R5are independently hydrogen, alkyl, alkenyl, allyl, vinyl, aryl, aminoalkyl, alkanol, haloalkyl, hydroxyalkyl, ethereal, heteroaryl or heterocyclic. By way of further example, in one such embodiment R4and R5are independently hydrogen, alkyl, alkenyl, aminoalkyl, alkanol, aryl, haloalkyl, hydroxyalkyl, ethereal, heteroaryl or heterocyclic. By way of further example, in one suchembodiment R4and R5(in combination with the nitrogen atom to which they are attached) together constitute part of a ring structure, so that the monomer as described by Formula 1 a is a nitrogen-containing heterocycle (e.g. , piperidine). By way of further example, in one embodiment R4and R5are independently hydrogen, aliphatic or heteroaliphatic. By way of further example, in one embodiment R4and R5areindependently hydrogen, allyl, or aminoalkyl. By way of further example, in each of the embodiments recited in this paragraph, R6may be methylene, ethylene or propylene, and R6i and R62 may independently be hydrogen, allyl or aminoalkyl.

[0216] In some embodiments, the crosslinked polymer comprises the residue of an amine corresponding to Formula 1 c:R 7\ R8Formula 1 cwherein R7is hydrogen, aliphatic or heteroaliphatic and R8is aliphatic or heteroaliphatic. For example, in one such embodiment, for example, R7is hydrogen and R8is aliphatic or heteroaliphatic. By way of further example, in one such embodiment R7and R8are independently aliphatic or heteroaliphatic. By way of further example, in one such embodiment at least one of R7and R8comprises an allyl moiety. By way of further example, in one such embodiment at least one of R7and R8comprises an aminoalkyl moiety. By way of further example, in one such embodiment R7and R8each comprise an allyl moiety. By way of further example, in one such embodiment R7and R8each comprise an aminoalkyl moiety. By way of further example, in one such embodiment R7comprises an allyl moiety and R8comprises an aminoalkyl moiety.

[0217] In some embodiments, the crosslinked polymer comprises the residue of an amine corresponding to Formula 2:Formula 2 wherein m and n are independently non-negative integers;R10, R20, R30, and R40are independently hydrogen, hydrocarbyl, or substituted hydrocarbyl;X2is hydrocarbyl or substituted hydrocarbyl; each X11 is independently hydrogen, hydrocarbyl, substituted hydrocarbyl, hydroxyl, amino, boronic acid, or halo; and z is a non-negative number.

[0218] In one embodiment, the crosslinked polymer comprises the residue of an amine corresponding to Formula 2, the crosslinked polymer is prepared by(i) substitution polymerization of the amine corresponding to Formula 2 with apolyfunctional crosslinker (optionally also comprising amine moieties) or (2) radical polymerization of an amine corresponding to Formula 2, and m and n are independently 0, 1 , 2 or 3 and n is 0 or 1 .

[0219] In one embodiment, the crosslinked polymer comprises the residue of an amine corresponding to Formula 2, the crosslinked polymer is prepared by(i) substitution polymerization of the amine corresponding to Formula 2 with apolyfunctional crosslinker (optionally also comprising amine moieties) or (2) radical polymerization of an amine corresponding to Formula 2, and R0, R20, R30, and R40are independently hydrogen, aliphatic, aryl, heteroaliphatic, or heteroaryl. By way of further example, in one such embodiment R-m, R20, R30, and R40are independently hydrogen, aliphatic, or heteroaliphatic. By way of further example, in one such embodiment R-io, R2o, R30, and R40are independently hydrogen, alkyl, allyl, vinyl, or aminoalkyl. By way of further example, in one such embodiment R-10, R20, R30, and R40are independently hydrogen, alkyl, allyl, vinyl, -(CH2)dNH2, -(CH2)dN[(CH2)eNH2)]2 where d and e are independently 2-4. In each of the foregoing exemplary embodiments of this paragraph, m and z may independently be 0, 1 , 2 or 3 and n is 0 or 1.

[0220] In one embodiment, the crosslinked polymer comprises the residue of an amine corresponding to Formula 2, the crosslinked polymer is prepared by(i) substitution polymerization of the amine corresponding to Formula 2 with apolyfunctional crosslinker (optionally also comprising amine moieties) or (2) radical polymerization of an amine corresponding to Formula 2, and X2is aliphatic orheteroaliphatic. For example, in one such embodiment X2is aliphatic or heteroaliphatic and R-io, R20, R30, and R40are independently hydrogen, aliphatic, heteroaliphatic. By way of further example, in one such embodiment X2is alkyl or aminoalkyl and R0, R20, R30, and R40are independently hydrogen, aliphatic, or heteroaliphatic. By way of further example, in one such embodiment X2is alkyl or aminoalkyl and R-io, R20, R30, and R40are independently hydrogen, alkyl, allyl, vinyl, or aminoalkyl. In each of the foregoing exemplary embodiments of this paragraph, m and z may independently be 0, 1 , 2 or 3 and n is 0 or 1 .

[0221] In one embodiment, the crosslinked polymer comprises the residue of an amine corresponding to Formula 2, the crosslinked polymer is prepared by(i) substitution polymerization of the amine corresponding to Formula 2 with apolyfunctional crosslinker (optionally also comprising amine moieties) or (2) radical polymerization of an amine corresponding to Formula 2, and m is a positive integer. For example, in one such embodiment m is a positive integer, z is zero and R2o is hydrogen, aliphatic or heteroaliphatic. By way of further example, in one such embodiment m is a positive integer (e.g., 1 to 3), z is a positive integer (e.g., 1 to 2), Xn is hydrogen, aliphatic or heteroaliphatic, and R2o is hydrogen, aliphatic or heteroaliphatic. By way of further example, in one such embodiment m is a positive integer, z is zero, one or two, Xn is hydrogen alkyl, alkenyl, or aminoalkyl, and R20is hydrogen, alkyl, alkenyl, or aminoalkyl.

[0222] In one embodiment, the crosslinked polymer comprises the residue of an amine corresponding to Formula 2, the crosslinked polymer is prepared by(i) substitution polymerization of the amine corresponding to Formula 2 with apolyfunctional crosslinker (optionally also comprising amine moieties) or (2) radical polymerization of an amine corresponding to Formula 2, and n is a positive integer and R30is hydrogen, aliphatic or heteroaliphatic. By way of further example, in one such embodiment n is 0 or 1 , and R30is hydrogen, alkyl, alkenyl, or aminoalkyl.

[0223] In one embodiment, the crosslinked polymer comprises the residue of an amine corresponding to Formula 2, the crosslinked polymer is prepared by(i) substitution polymerization of the amine corresponding to Formula 2 with apolyfunctional crosslinker (optionally also comprising amine moieties) or (2) radical polymerization of an amine corresponding to Formula 2, and m and n are independently non-negative integers and X2is aliphatic or heteroaliphatic. For example, in one such embodiment m is 0 to 2, n is 0 or 1 , X2is aliphatic or heteroaliphatic, and Rio, R2o, R30, and R40are independently hydrogen, aliphatic, or heteroaliphatic. By way of further example, in one such embodiment m is 0 to 2, n is 0 or 1 , X2is alkyl or aminoalkyl, and R10, R20, R30, and R40are independently hydrogen, aliphatic, or heteroaliphatic. By way of further example, in one such embodiment m is 0 to 2, n is 0 or 1 , X2is alkyl or aminoalkyl, and R0, R20, R30, and R40are independently hydrogen, alkyl, alkenyl, or aminoalkyl.

[0224] In some embodiments, the crosslinked polymer comprises the residue of an amine corresponding to Formula 2a and the crosslinked polymer is prepared by substitution polymerization of the amine corresponding to Formula 2a with apolyfunctional crosslinker (optionally also comprising amine moieties):Formula 2a wherein m and n are independently non-negative integers; each Rii is independently hydrogen, hydrocarbyl, heteroaliphatic, or heteroaryl; R21and R3, are independently hydrogen or heteroaliphatic;R4i is hydrogen, substituted hydrocarbyl, or hydrocarbyl;X2is alkyl or substituted hydrocarbyl; each X2is independently hydrogen, hydroxy, amino, aminoalkyl, boronic acid or halo; and z is a non-negative number.

[0225] In one embodiment, the crosslinked polymer comprises the residue of an amine corresponding to Formula 2a, the crosslinked polymer is prepared by substitution polymerization of the amine corresponding to Formula 1 with apolyfunctional crosslinker (optionally also comprising amine moieties). For example, in one such embodiment, m and z are independently 0, 1 , 2 or 3, and n is 0 or 1 .

[0226] In one embodiment, the crosslinked polymer comprises the residue of an amine corresponding to Formula 2a, the crosslinked polymer is prepared by substitution polymerization of the amine corresponding to Formula 2a with apolyfunctional crosslinker (optionally also comprising amine moieties), and each R-n isindependently hydrogen, aliphatic, aminoalkyl, haloalkyl, or heteroaryl, R2i and R3i are independently hydrogen or heteroahphatic and R4i is hydrogen, aliphatic, aryl, heteroahphatic, or heteroaryl. For example, in one such embodiment each R-n is hydrogen, aliphatic, aminoalkyl, or haloalkyl, R2i and R3i are independently hydrogen or heteroahphatic and R4i is hydrogen, alkylamino, aminoalkyl, aliphatic, or heteroahphatic. By way of further example, in one such embodiment each R-n is hydrogen, aliphatic, aminoalkyl, or haloalkyl, R2i and R3are hydrogen or aminoalkyl, and R4is hydrogen, aliphatic, or heteroahphatic. By way of further example, in one such embodiment each Rii and R4i is independently hydrogen, alkyl, or aminoalkyl, and R2i and R3i are independently hydrogen or heteroahphatic. By way of further example, in one such embodiment each R-n and R4is independently hydrogen, alkyl, -(CH2)dNH2, - (CH2)dN[(CH2)eNH2)]2where d and e are independently 2-4, and R2i and R3i are independently hydrogen or heteroahphatic. In each of the foregoing exemplary embodiments of this paragraph, m and z may independently be 0, 1 , 2 or 3, and n is 0 or 1 .

[0227] Exemplary amines for the synthesis of polymers comprising repeat units corresponding to Formula 2a include, but are not limited to, amines appearing in Table A.Table A

[0228] Exemplary crosslinkers for the synthesis of polymers comprising the residue of amines corresponding to Formula 2a include but are not limited to crosslinkers appearing in Table B.Table B

[0229] In some embodiments, the crosslinked polymer comprises the residue of an amine corresponding to Formula 2b and the crosslinked polymer is prepared by radical polymerization of an amine corresponding to Formula 2b:Formula 2b wherein m and n are independently non-negative integers; each R-12 is independently hydrogen, substituted hydrocarbyl, or hydrocarbyl; R22 and R32are independently hydrogen substituted hydrocarbyl, or hydrocarbyl; R42is hydrogen, hydrocarbyl or substituted hydrocarbyl;X2is alkyl, aminoalkyl, or alkanol; each X-13 is independently hydrogen, hydroxy, alicyclic, amino, aminoalkyl, halogen, alkyl, heteroaryl, boronic acid or aryl; z is a non-negative number, and the amine corresponding to Formula 2b comprises at least one ally I group.

[0230] In one embodiment, the crosslinked polymer comprises the residue of an amine corresponding to Formula 2b, the crosslinked polymer is prepared by radical polymerization of an amine corresponding to Formula 2b, and m and z areindependently 0, 1 , 2 or 3, and n is 0 or 1 .

[0231] In one embodiment, the crosslinked polymer comprises the residue of an amine corresponding to Formula 2b, the crosslinked polymer is prepared by radical polymerization of an amine corresponding to Formula 1 , and (i) Ri2or R42independently comprise at least one allyl or vinyl moiety, (ii) m is a positive integer and R22 comprises at least one allyl or vinyl moiety, and / or (iii) n is a positive integer and R32comprises at least one allyl moiety. For example, in one such embodiment, m and z are independently 0, 1 , 2 or 3 and n is 0 or 1. For example, in one such embodiment R-12 or R42, in combination comprise at least two allyl or vinyl moieties. By way of further example, in in one such embodiment, m is a positive integer and R-12, R22 and R42, in combination comprise at least two allyl or vinyl moieties. By way of further example, in in one such embodiment, n is a positive integer and R12, R32 and R42, in combination comprise at least two allyl or vinyl moieties. By way of further example, in in one such embodiment, m is a positive integer, n is a positive integer and R-12, R22, R32 and R42, in combination, comprise at least two allyl or vinyl moieties.

[0232] In one embodiment, the crosslinked polymer comprises the residue of an amine corresponding to Formula 2b, the crosslinked polymer is prepared by radical polymerization of an amine corresponding to Formula 2b, and each R12 is independently hydrogen, aminoalkyl, allyl, or vinyl, R22 and R32are independently hydrogen, alkyl, aminoalkyl, haloalkyl, alkenyl, alkanol, heteroaryl, alicyclic heterocyclic, or aryl, and R42is hydrogen or substituted hydrocarbyl. For example, in one such embodiment each R2is aminoalkyl, allyl or vinyl, R22 and R32are independently hydrogen, alkyl, aminoalkyl, haloalkyl, alkenyl, or alkanol, and R42is hydrogen or substituted hydrocarbyl. By way of further example, in one such embodiment each Ri2and R42is independently hydrogen, alkyl, allyl, vinyl, -(CH2)dNH2or -(CH2)dN[(CH2)eNH2]2 where d and e are independently 2-4, and R22 and R32are independently hydrogen or heteroaliphatic.

[0233] Exemplary amines and crosslinkers (or the salts thereof, for example the hydrochloric acid, phosphoric acid, sulfuric acid, or hydrobromic acid salts thereof) for the synthesis of polymers described by Formula 2b include but are not limited to the ones in Table C.Table C

[0234] In some embodiments, the crosslinked polymer is derived from a reaction of the resulting polymers that utilize monomers described in any of Formulae 1 , 1 a, 1 b, 1 c, 2, 2a and 2b or a linear polymer comprised of a repeat unit described by Formula 3 with external crosslinkers or pre-existing polymer functionality that can serve as crosslinking sites. Formula 3 can be a repeat unit of a copolymer or terpolymer where Xi5is either a random, alternating, or block copolymer. The repeating unit in Formula 3 can also represent the repeating unit of a polymer that is branched, or hyperbranched, wherein the primary branch point can be from any atom in the main chain of the polymer:Formula 3 whereinR-I 5, R-I6 and Ri7are independently hydrogen, hydrocarbyl, substitutedhydrocarbyl, hydroxyl, amino, boronic acid or halo;X5is hydrocarbyl, substituted hydrocarbyl, oxo (-0-), or amino and z is a non-negative number.

[0235] In one embodiment, R5, R6and R7are independently hydrogen, aryl, or heteroaryl, X5is hydrocarbyl, substituted hydrocarbyl, oxo or amino, and m and z are non-negative integers. In another embodiment, Ri5, Ri6and Ri7are independently aliphatic or heteroaliphatic, X5is hydrocarbyl, substituted hydrocarbyl, oxo (-0-) or amino, and m and z are non-negative integers. In another embodiment, R5, R6andR-17 are independently unsaturated aliphatic or unsaturated heteroaliphatic, X5is hydrocarbyl, substituted hydrocarbyl, oxo, or amino, and z is a non-negative integer. In another embodiment, Ri5, Ri6and R17 are independently alkyl or heteroalkyl, X5is hydrocarbyl, substituted hydrocarbyl, oxo, or amino, and z is a non-negative integer. In another embodiment, Ri5, Ri6and Ri7are independently alkylamino, aminoalkyl, hydroxyl, amino, boronic acid, halo, haloalkyl, alkanol, or ethereal, X5is hydrocarbyl, substituted hydrocarbyl, oxo, or amino, and z is a non-negative integer. In another embodiment, R5, R6and R7are independently hydrogen, hydrocarbyl, substituted hydrocarbyl, hydroxyl, amino, boronic acid or halo, X5is oxo, amino, alkylamino, ethereal, alkanol, or haloalkyl, and z is a non-negative integer.

[0236] Exemplary crosslinking agents that may be used in radicalpolymerization reactions include, but are not limited to, one or more multifunctional crosslinking agents such as: 1 ,4-bis(allylamino)butane, 1 ,2-bis(allylamino)ethane, 2- (allylamino)-l -[2-(allylamino)ethylamino]ethane, 1 ,3-bis(allylamino)propane, 1 ,3- bis(allylamino)-2-propanol, triallylamine, diallylamine, divinylbenzene, 1 ,7-octadiene, 1 ,6-heptadiene, 1 ,8-nonadiene, 1 ,9-decadiene, 1 ,4-divinyloxybutane, 1 ,6- hexamethylenebisacrylamide, ethylene bisacrylamide, Ν,Ν'- bis(vinylsulfonylacetyl)ethylene diamine, 1 ,3-bis(vinylsulfonyl) 2-propanol, vinylsulfone, Ν,Ν'-methylenebisacrylamide polyvinyl ether, polyallylether, divinylbenzene, 1 ,4- divinyloxybutane, and combinations thereof.

[0237] Crosslinked polymers derived from the monomers and polymers in formulas 1 through 3 may be synthesized either in solution or bulk or in dispersed media. Examples of solvents that are suitable for the synthesis of polymers of the present disclosure include, but are not limited to water, low boiling alcohols (methanol, ethanol, propanol, butanol), dimethylformamide, dimethylsulfoxide, heptane, chlorobenzene, toluene.

[0238] Alternative polymer processes may include, a lone polymerization reaction, stepwise addition of individual starting material monomers via a series of reactions, the stepwise addition of blocks of monomers, combinations or any other method of polymerization such as living polymerization, direct polymerization, indirectpolymerization, condensation, radical, emulsion, precipitation approaches, spray dry polymerization or using some bulk crosslinking reaction methods and size reduction processes such as grinding, compressing, extrusion. Processes can be carried out as a batch, semi-continuous and continuous processes. For processes in dispersed media, the continuous phase can be non-polar solvents, such as toluene, benzene,hydrocarbon, halogenated solvents, super critical carbon dioxide. With a direct suspension reaction, water can be used and salt can be used to tune the properties of the suspension.

[0239] The starting molecules described in formulas 1 through 3 may be copolymerized with one or more other monomers of the invention, oligomers or other polymerizable groups. Such copolymer architectures can include, but are not limited to, block or block-like polymers, graft copolymers, and random copolymers. Incorporation of monomers described by formulas 1 through 3 can range from 1 % to 99%. In some embodiments, the incorporation of comonomer is between 20% and 80%.

[0240] Non-limiting examples of comonomers which may be used alone or in combination include: styrene, allylamine hydrochloride, substituted allylaminehydrochloride, substituted styrene, alkyl acrylate, substituted alkyl acrylate, alkyl methacrylate, substituted alkyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, N-alkylacrylamide, N-alkylmethacrylamide, N,N-dialkylacrylamide, Ν,Ν-dialkylmethacrylamide, isoprene, butadiene, ethylene, vinyl acetate, N-vinyl amide, maleic acid derivatives, vinyl ether, allyle, methallyl monomers and combinations thereof. Functionalized versions of these monomers may also be used. Additional specific monomers or comonomers that may be used in this invention include, but are not limited to, 2-propen-1 -ylamine, 1 -(allylamino)-2-aminoethane, 1 -[N-allyl(2- aminoethyl)amino]-2-aminoethane, methyl methacrylate, ethyl methacrylate, propyl methacrylate (all isomers), butyl methacrylate (all isomers), 2-ethylhexyl methacrylate, isobornyl methacrylate, methacrylic acid, benzyl methacrylate, phenyl methacrylate, methacrylonitrile, amethylstyrene, methyl acrylate, ethyl acrylate, propyl acrylate (all isomers), butyl acrylate (all isomers), 2-ethylhexyl acrylate, isobornyl acrylate, acrylic acid, benzyl acrylate, phenyl acrylate, acrylonitrile, styrene, glycidyl methacrylate, 2- hydroxyethyl methacrylate, hydroxypropyl methacrylate (all isomers), hydroxybutylmethacrylate (all isomers), Ν,Ν-dimethylaminoethyl methacrylate, N,N-diethylaminoethyl methacrylate, triethyleneglycol methacrylate, itaconic anhydride, itaconic acid, glycidyl acrylate, 2-hydroxyethyl acrylate, hydroxypropyl acrylate (all isomers), hydroxybutyl acrylate (all isomers), Ν,Ν-dimethylaminoethyl acrylate, Ν,Ν-diethylaminoethyl acrylate, triethyleneglycol acrylate, methacrylamide, N-methylacrylamide, N,N- dimethylacrylamide, N-tert-butylmethacrylamide, N-N-butylmethacrylamide, N- methylolmethacrylamide, N-ethylolmethacrylamide, N-tert-butylacryl amide, N- Nbutylacrylamide, N-methylolacrylamide, N-ethylolacrylamide, 4-acryloylmorpholine, vinyl benzoic acid (all isomers), diethylaminostyrene (all isomers), a-methylvinyl benzoic acid (all isomers), diethylamino a-methylstyrene (all isomers), p-vinylbenzene sulfonic acid, p-vinylbenzene sulfonic sodium salt, trimethoxysilylpropyl methacrylate,triethoxysilylpropyl methacrylate, tributoxysilylpropyl methacrylate,dimethoxymethylsilylpropyl methacrylate, diethoxymethylsilylpropyl methacrylate, dibutoxymethylsilylpropyl methacrylate, diisopropoxymethylsilylpropyl methacrylate, dimethoxysilylpropyl methacrylate, diethoxysilylpropyl methacrylate, dibutoxysilylpropyl methacrylate, diisopropoxysilylpropyl methacrylate, trimethoxysilylpropyl acrylate, triethoxysilylpropyl acrylate, tributoxysilylpropyl acrylate, dimethoxymethylsilylpropyl acrylate, diethoxymethylsilylpropyl acrylate, dibutoxymethylsilylpropyl acrylate, diisopropoxymethylsilylpropyl acrylate, dimethoxysilylpropyl acrylate, diethoxysilylpropyl acrylate, dibutoxysilylpropyl acrylate, diisopropoxysilylpropyl acrylate, maleic anhydride, N-phenylmaleimide, N-butylmaleimide, N-vinylformamide, N-vinyl acetamide, allylamine, methallylamine, allylalcohol, methyl-vinylether, ethylvinylether, butylvinyltether, butadiene, isoprene, chloroprene, ethylene, vinyl acetate, and combinations thereof.

[0241] Additional modification to the preformed crosslinked polymer can be achieved through the addition of modifiers, including but not limited to amine monomers, additional crosslinkers, and polymers. Modification can be accomplished through covalent or non-covalent methods. These modifications can be evenly or unevenly dispersed throughout the preformed polymer material, including modifications biased to the surface of the preformed crosslinked polymer. Furthermore, modifications can be made to change the physical properties of the preformed crosslinked polymer, including but not limited to reactions that occur with remaining reactive groups such as haloalkylgroups and allyl groups in the preformed polymer. Reactions and modifications to the preformed crosslinked polymer can include but are not limited to acid-base reactions, nucleophilic substitution reactions, Michael reactions, non-covalent electrostatic interactions, hydrophobic interactions, physical interactions (crosslinking) and radical reactions.

[0242] In one embodiment, the post-polymerization crosslinked amine polymer is a crosslinked amine polymer comprising a structure corresponding toFormula 4:Formula 4 wherein each R is indendently hydrogen or an ethylene crosslink between two nitrogen atoms of the crosslinked amine polymer (N^ ) and a, b, c, and m are integers. Typically, m is a large integer indicating an extended polymer network. In one such embodiment, a ratio of the sum of a and b to c (i.e., a+b:c) is in the range of about 1 :1 to 5: 1. For example, in one such embodiment a ratio of the sum of a and b to c (i.e., a+b:c) is in the range of about 1 .5: 1 to 4: 1 . By way of further example, in one such embodiment a ratio of the sum of a and b to c (i.e., a+b:c) is in the range of about 1 .75: 1 to 3: 1 . For example, in one such embodiment a ratio of the sum of a and b is 57, c is 24 and m is large integer indicating an extended polymer network. In each of the foregoing embodiments a ratio of the sum of a and b to c (i.e., a+b:c) may be in the range of about 2: 1 to 2.5:1 . For example, in such embodiments the ratio of the sum of a and b to c (i.e. , a+b:c) may be in the range of about 2.1 : 1 to 2.2: 1 . By way of further example, in such embodiments the ratio of the sum of a and b to c (i.e., a+b:c) may be in the rangeof about 2.2: 1 to 2.3: 1 . By way of further example, in such embodiments the ratio of the sum of a and b to c (i.e., a+b:c) may be in the range of about 2.3: 1 to 2.4: 1 . By way of further example, in such embodiments the ratio of the sum of a and b to c (i.e., a+b:c) may be in the range of about 2.4: 1 to 2.5: 1 . In each of the foregoing embodiments, each R may independently be hydrogen or an ethylene crosslink between two nitrogen atoms. Typically, however, 35-95% of the R substituents will be hydrogen and 5-65% will be an ethylene crosslink (N).For example, in one such embodiment, 50-95% of the R substituents will be hydrogen and 5-50% will be an ethylene crosslink (in one such embodiment, 60-90% of the R substituents are hydrogen and 10-40% are an ethylene crosslink. By way of further example, in one such embodiment, 65-90% ofNthe R substituents are hydrogen and 10-35% are an ethylene crosslink. (N) . By way of further example, in one such embodiment, 70-90% of the R substituents are hydrogen and 10-30% are an ethylene crosslink. By way of further example, in one such embodiment, 75-85% of the R substituents are hydrogen and 15-25% are an ethylene crosslink. By way of further example, in one such embodiment, 65-75% of the R substituents are hydrogen and 25-35% are an ethylene crosslink. By way of further example, in one such embodiment, 55-65% of the R substituents are hydrogen and 35- 45% are an ethylene crosslink. In some embodiments, a, b, c and R are such that the carbon to nitrogen ratio of the polymer of Formula 4 may range from about 2:1 to about 6: 1 , respectively. For example, in one such embodiment, the carbon to nitrogen ratio of the polymer of Formula 4 may range from about 2.5: 1 to about 5: 1 , respectively. By way of further example, in one such embodiment, the carbon to nitrogen ratio of the polymer of Formula 4 may range from about 3: 1 to about 4.5: 1 , respectively. By way of further example, in one such embodiment, the carbon to nitrogen ratio of the polymer of Formula 4 may range from about 3.25: 1 to about 4.25: 1 , respectively. By way of further example, in one such embodiment, the carbon to nitrogen ratio of the polymer of Formula 4 may range from about 3.4:1 to about 4:1 , respectively. By way of furtherexample, in one such embodiment, the carbon to nitrogen ratio of the polymer of Formula 4 may range from about 3.5:1 to about 3.9: 1 , respectively. By way of further example, in one such embodiment, the carbon to nitrogen ratio of the polymer of Formula 4 may range from about 3.55: 1 to about 3.85: 1 , respectively. In each of the foregoing embodiments recited in this paragraph, the polymer of Formula 4 is derived from monomers and crosslinkers, each of which comprise less than 5 wt% oxygen.

[0243] In certain embodiments, polymers in which crosslinking and / or entanglement were increased were found to have lower swelling than those with lower crosslinking and / or entanglement, yet also had a binding capacity for target ion (e.g., chloride) that was as great as or greater than the lower crosslinking and / orentanglement polymers while binding of interfering ions such as phosphate were significantly reduced. The selectivity effect may be introduced in two different manners: 1 ) Overall capacity was sacrificed for chloride specificity. Crosslinkers that don't include chloride binding sites (e.g., epichlorohydrin) allow for increased crosslinking while overall capacity is decreased proportional to the amount of crosslinker incorporated into the polymer. 2) Overall capacity is preserved for chloride specificity: Crosslinkers that include chloride binding sites (e.g., diallylamines) allow for increased crosslinking while overall capacity is staying the same or is reduced by only a small amount.

[0244] As previously noted, crosslinked polymers having a high capacity for chloride binding and high selectivity for chloride over other competing anions such as phosphate may be prepared in a two-step process in accordance with one embodiment of the present disclosure. In general, the selectivity of the polymer is a function of its crosslinking density and the capacity of the polymer is a function of the free amine density of the crosslinked polymer. Advantageously, the two-step process disclosed herein provides both, high capacity for chloride binding, and high selectivity for chloride over other competing ions by relying primarily upon carbon-carbon crosslinking in the first step, and nitrogen-nitrogen crosslinking in the second step.

[0245] In the first step, the crosslinking is preferably capacity-sparing, i.e., free amine sparing, crosslinking from carbon to carbon. In the second step, the crosslinking is amine-consuming and is directed towards tuning for selectivity. Based on the desired high capacity, the C-N ratio is preferably optimized to maximize amine functionalities forHCI binding, while still maintaining a spherical polymer particle of controlled particle size to ensure nonabsorption and acceptable mouth feel that is stable under Gl conditions. The preferred extent of carbon-carbon crosslinking achieved after the first step is sufficient to permit the resulting bead to swell between 4X and 6X in water (i.e., a Swelling Ratio of 4 to 6).

[0246] In one embodiment, crosslinked polymers having a high capacity for chloride binding and high selectivity for chloride over other competing anions such as phosphate may be prepared in a two-step process, and the product of the first polymerization step is preferably in the form of beads whose diameter is controlled in the 5 to 1000 micromer range, preferably 10 to 500 micrometers and most preferred 40 - 180 micrometers.

[0247] The product of the first polymerization step is preferably in the form of beads whose Swelling Ratio in water is between 2 and 10, more preferably about 3 to about 8, and most preferably about 4 to about 6.

[0248] Additionally, if the crosslinked polymer beads resulting from the first polymerization step are protonated, this may reduce the amount of nitrogen-nitrogen crosslinking in the second crosslinking step. Accordingly, in certain embodiments the preformed amine polymer is at least partially deprotonated by treatment with a base, preferably a strong base such as a hydroxide base. For example, in one embodiment the base may be NaOH, KOH, NH4OH, NaHC03, Na2C03, K2C03, LiOH, Li2C03, CsOH or other metal hydroxides. If the charges are removed from the preformed crosslinked amine polymer bead by deprotonation, the bead will tend to collapse and thecrosslinking agent used in the second step may not be able to access binding sites on the polymer unless the bead is prevented from collapsing. One means of preventing the crosslinked polymer bead from collapsing is the use of a swelling agent such as water to swell the bead, thereby allowing the second-step crosslinker to access binding sites.

[0249] The preformed polymer may be crosslinked to form the post- polymerization crosslinked polymer using any of a range of crosslinking compounds containing at least two amine-reactive functional groups. In one such embodiment, thecrosslinker is a compound containing at least two amine-reactive groups selected from the group consisting of halides, epoxides, phosgene, anhydrides, carbamates, carbonates, isocyanates, thioisocyanates, esters, activated esters, carboxylic acids and derivatives thereof, sulfonates and derivatives thereof, acyl halides, aziridines, α,β- unsaturated carbonyls, ketones, aldehydes, and pentafluoroaryl groups. Thecrosslinker may be, for example, any of the crosslinkers disclosed herein, including a crosslinker selected from Table B. By way of further example, in one such embodiment the crosslinker is a dihalide such as a dichloroalkane.

[0250] As noted above, in certain embodiments a swelling agent for the preformed amine polymer may be included in the reaction mixture for the second polymerization step along with the crosslinking agent. In general, the swelling agent and the crosslinking agent may be miscible or immiscible and the swelling agent may be any composition or combination of compositions that have the capacity to swell the preformed amine polymer. Exemplary swelling agents include polar solvents such as water, methanol, ethanol, n-propanol, isopropanol, n-butanol, formic acid, acetic acid, acetonitrile, dimethylformamide, dimethylsulfoxide, nitromethane, propylene carbonate, or a combination thereof. Additionally, the amount of swelling agent included in the reaction mixture will typically be less than absorption capacity of the preformed amine polymer for the swelling agent. For example, it is generally preferred that the weight ratio of swelling agent to preformed polymer in the reaction mixture be less than 4: 1 . By way of further example, in some embodiments the weight ratio of swelling agent to preformed polymer in the reaction mixture will be less than 3: 1 . By way of further example, in some embodiments the weight ratio of swelling agent to preformed polymer in the reaction mixture will be less than 2: 1. By way of further example, in some embodiments the weight ratio of swelling agent to preformed polymer in the reaction mixture will be less than 1 : 1 . By way of further example, in some embodiments the weight ratio of swelling agent to preformed polymer in the reaction mixture will be less than 0.5: 1. By way of further example, in some embodiments the weight ratio of swelling agent to preformed polymer in the reaction mixture will be less than 0.4: 1. By way of further example, in some embodiments the weight ratio of swelling agent to preformed polymer in the reaction mixture will be less than 0.3:1 . In general, however,the weight ratio of swelling agent to preformed polymer in the reaction mixture will typically be at least 0.05: 1 , respectively.

[0251] In general, the crosslinked polymers may be crosslinkedhomopolymers or crosslinked copolymers comprising free amine moieties. The free amine moieties may be separated, for example, by the same or varying lengths of repeating linker (or intervening) units. In some embodiments, the polymers comprise repeat units containing an amine moiety and an intervening linker unit. In other embodiments, multiple amine-containing repeat units are separated by one or more linker units. Additionally, the polyfunctional crosslinkers may comprise HCI binding functional groups, e.g., amines, ("active crosslinkers") or may lack HCI binding functional groups such as amines ("passive crosslinkers").

[0252] In a preferred embodiment, the first polymerization (crosslinking) step yields preformed amine polymer beads having a target size and chloride binding capacity. For example, in one such embodiment the beads have a chloride binding capacity of at least 10 mmol / g in Simulated Gastric Fluid ("SGF") and a Swelling Ratio in the range of 1 to 6. The resulting preformed amine polymer is then preferably (at least partially) deprotonated with a base and combined with a non-protonating swelling agent to swell the free amine polymer without protonating the amine functions.Furthermore, the amount of the non-protonating swelling agent is selected to tune the subsequent degree of crosslinking effectively forming a template that is then locked into place via the amine consuming crosslinking step. In the second crosslinking step, the swollen, deprotonated preformed amine polymer is crosslinked with a crosslinker containing amine reactive moieties to form a post-polymerization crosslinked polymer.

[0253] In general, selectivity for chloride over other competing ions is achieved with highly crosslinked polymers. For example, relatively high chloride binding capacity maybe be attained by reacting a preformed amine polymer bead with neat crosslinker in the presence of a swelling agent (water). While this "non-dispersed" reaction provides access to high selectivity for chloride over competing ions in the SIB assay, it also results in macroscopically (and microscopically) aggregated polymer beads. Accordingly, it is advantageous to include a solvent (e.g., heptane) in thesecond crosslinking step to disperse the preformed crosslinked polymer beads so as to avoid inter-bead reactions and resulting aggregation. The use of too much solvent (dispersant), however, can dilute the reaction solution to the point where the resulting bead is not sufficiently crosslinked to have the desired selectivity for chloride over other competing anions. By using a crosslinking agent that also functions as a solvent (dispersant), however, sufficient solvent (dispersant) may be included in the reaction mixture to avoid inter-bead reactions and aggregation without diluting the mixture to the point where the degree of amine-consuming crosslinking is insufficient. For example, in an effort to utilize the dispersing properties of a solvent (to avoid aggregation during the reaction) while maintaining reactivity, DCE and DCP were used neat, thus performing a dual purpose role, as both solvent (dispersant) and crosslinker. Interestingly, DCE was discovered to have excellent dispersal properties as a solvent, when compared to similar reactions with DCP and / or heptane. Additionally, less aggregation was observed when the beads were first dispersed in DCE and then in a second operation, the water is added to swell the beads. If water is added to the preformed amine polymer before the bead is dispersed in the DCE, aggregation may occur.

[0254] The use of 1 ,2-dichloroethane ("DCE") as the crosslinking solvent also generates HCI molecules during the second step. These HCI molecules protonate some of the free amine sites which block the reaction sites for the crosslinking reaction and thereby limit the number of binding sites available for crosslinking. Consequently, the use of DCE creates a self-limiting effect on the secondary crosslinking.

[0255] In each of the foregoing embodiments, the reaction mixture may contain a wide range of amounts of crosslinking agents. For example, in oneembodiment the crosslinker may be used in large excess relative to the amount of preformed amine polymer in the reaction mixtures. Stated differently, in suchembodiments the crosslinking agent is a crosslinking solvent, i.e. , it is both a solvent for the reaction mixture and a crosslinking agent for the preformed amine polymer. In such embodiments, other solvents may optionally be included in the reaction mixture but are not required. Alternatively, the preformed amine polymer, swelling agent andcrosslinker may be dispersed in a solvent that is miscible with the crosslinker and immiscible with the swelling agent. For example, in some embodiments the swellingagent may be a polar solvent; in some such embodiments, for example, the swelling agent may comprise water, methanol, ethanol, n-propanol, isopropanol, formic acid, acetic acid, acetonitrile, / V, / V-dimethylformamide, dimethylsulfoxide, nitromethane, or a combination thereof. By way of further example, when the swelling agent comprises a polar solvent, the solvent system for the reaction mixture will typically comprise a non- polar solvent such as pentane, cyclopentane, hexane, cyclohexane, benzene, toluene, 1 ,4-dioxane, chloroform, diethyl ether, dichloromethane, dichloroethane,dichloropropane, dichlorobutane, or a combination thereof. In certain embodiments, the crosslinker and the solvent may be the same; i.e., the solvent is a crosslinking solvent such as 1 ,2-dichloroethane, 1 ,3-dichloropropane, 1 ,4-dichlorobutane or a combination thereof.

[0256] It is notable that in a crosslinking solvent (e.g., a DCE-dispersed reaction), there is a large excess of crosslinker regardless of the amount of crosslinking solvent (e.g. , DCE) used to disperse the bead (e.g., both 1 g:3 ml_::bead:DCE and 1 g: 10 ml_::bead:DCE are a large excess of crosslinker, most of which is not consumed during the reaction). Despite this, the relative degree of crosslinking, and theperformance in SIB assay, are unaffected by changes in the ratio of reactive crosslinker to polymer bead. This is possible because the reaction is limited by the acid-neutralizing capacity of the polymer bead, rather than the amount of crosslinker (e.g. , DCE).

[0257] To more efficiently react with DCE or other crosslinker, the amines of the preformed polymer bead preferably have a free electron pair (neutral,deprotonated). As the free amines of the preformed polymer bead react with the crosslinker (e.g., DCE), HCI is produced and the amines become protonated, thus limiting the reaction. For this reason, the preformed amine polymer beads preferably start as the free amine in the second crosslinking step. If the preformed amine polymer bead is protonated after the first step of carbon-carbon crosslinking, amine-consuming crosslinking in the second step will be limited, thus reducing the desired selectivity for chloride over other competing ions. This has been demonstrated by adding known quantities of HCI to preformed amine polymer beads immediately before second step crosslinking with DCE (TABLE 7). When less than 3 mol % HCI (to amine in preformed polymer amine bead) is added prior to second step crosslinking, total chloride capacity(SGF) and chloride selectivity in SIB are similar to beads not treated with HCI in the second step. When greater than 5 mol % HCI (to amine in preformed polymer amine bead) is added prior to second step crosslinking, total chloride capacity (SGF) increases and chloride selectivity in SIB decreases, indicating lower incorporation of crosslinker.

[0258] The benefits of deprotonated preformed polymer beads in the second step crosslinking highlights the advantages of using two steps to achieve the final product. In the first step, to form the amine polymer bead, all monomers (e.g., allylamine and DAPDA) are protonated to remain in the aqueous phase and to avoid the radical transfer reactions that severely limit the polymerization of non-protonated allylamine (and derivatives). Once the bead is formed through carbon-carbon crosslinks, the bead can then be deprotonated and further crosslinked with an amine reactive crosslinker in a second step.

[0259] Given the large excess of dual crosslinker / solvent, mono-incorporation of this reagent can occur leading to alkyl chloride functional groups on the crosslinked polymer bead that are hydrophobic in nature and can increase non-specific interactions with undesirable solutes other than HCI that are more hydrophobic in nature. Washing with ammonium hydroxide solution converts the alkyl-chloride to alkyl-amine functions that are hydrophilic and minimize non-specific interactions with undesirable solutes. Other modifications that yield more hydrophilic groups than alkyl chloride such as -OH are suitable to quench mono-incorporated crosslinker / solvent.

[0260] Any of a range of polymerization chemistries may be employed in the first reaction step, provided that the crosslinking mechanism is primarily carbon-carbon crosslinking. Thus, in one exemplary embodiment, the first reaction step comprises radical polymerization. In such reactions, the amine monomer will typically be a mono- functional vinyl, allyl, or acrylamide (e.g., allylamine) and crosslinkers will have two or more vinyl, allyl or acrylamide functionalities (e.g. , diallylamine). Concurrentpolymerization and crosslinking occurs through radically initiated polymerization of a mixture of the mono- and multifunctional allylamines. The resulting polymer network is thusly crosslinked through the carbon backbone. Each crosslinking reaction forms a carbon-carbon bond (as opposed to substitution reactions in which a carbon-heteroatombond is formed during crosslinking). During the concurrent polymerization and crosslinking, the amine functionalities of the monomers do not undergo crosslinking reactions and are preserved in the final polymer (i.e. , primary amines remain primary, secondary amines remain secondary, and tertiary amines remain tertiary).

[0261] In those embodiments in which the first reaction step comprises radical polymerization, a wide range of initiators may be used including cationic and radical initiators. Some examples of suitable initiators that may be used include: the free radical peroxy and azo type compounds, such as azodiisobutyronitrile,azodiisovaleronitrile, dimethylazodiisobutyrate, 2,2'azo bis(isobutyronitrile), 2,2'- azobis(N,N'-dimethy1 -eneisobutyramidine)dihydrochloride, 2,2'-azobis(2- amidinopropane)dihydrochloride, 2,2'-azobis(N,N'-dimethyleneisobutyramidine ), 1 , 1 '- azo bis(l-cyclohexanecarbo-nitrile), 4,4'-azobis(4-cyanopentanoic acid), 2,2'- azobis(isobutyramide)dihydrate, 2,2'-azobis(2-methylpropane), 2,2'-azobis(2- methylbutyronitrile), VAZO 67, cyanopentanoic acid, the peroxypivalates,dodecylbenzene peroxide, benzoyl peroxide, di-t-butyl hydroperoxide, t-butylperacetate, acetyl peroxide, dicumyl peroxide, cumylhydroperoxide, dimethylbis(butylperoxy)hexane.

[0262] Exemplary amine-containing polymers as described above are more fully disclosed and exemplified in WO2016 / 094685 A1 and WO2014 / 197725 A1 , the entire contents of which are incorporated herein by reference.

[0263] In one embodiment, the pharmaceutical composition comprises a mixture of any of the previously-identified nonabsorbable materials. For example, in one embodiment the pharmaceutical composition comprises a mixture of a cation exchange composition with at least one anion exchange composition, amphoteric ion exchange composition, or neutral composition having the capacity to bind both protons and anions. In another embodiment, the pharmaceutical composition comprises a mixture of an anion exchange composition with at least one cation exchangecomposition, amphoteric ion exchange composition, or neutral composition having the capacity to bind both protons and anions. In yet another embodiment, thepharmaceutical composition comprises a mixture of a neutral composition having thecapacity to bind both protons and anions with at least one cation exchange composition, amphoteric ion exchange composition, or anion exchange composition.

[0264] As schematically depicted in Figs. 1A-1 C and in accordance with one embodiment, a nonabsorbabl free-amine polymer of the present disclosure is orally ingested and used to treat metabolic acidosis (including by increasing serumbicarbonate and normalizing blood pH) in a mammal by binding HCI in thegastrointestinal ("Gl") tract and removing HCI through the feces. Free-amine polymer is taken orally (Fig. 1A) at compliance enhancing dose targeted to chronically bind sufficient amounts of HCI to enable clinically meaningful increase in serum bicarbonate of 3 mEq / L. In the stomach (Fig. 1 B), free amine becomes protonated by binding H+. Positive charge o...

Claims

CLAIMSWhat is claimed is:1 . A method of treating an individual afflicted with an acid-base disorder characterized by a baseline serum bicarbonate value of less than 22 mEq / l, the method comprising oral administration of a daily dose of a pharmaceutical composition having the capacity to bind at least 5 mEq of a target species as it transits the digestive system to achieve a clinically significant increase in the serum bicarbonate value of at least 1 mEq / l from baseline within a treatment period not greater than 1 month, the target species being selected from the group consisting of protons, strong acids, and conjugate bases of strong acids.

2. A method of treating an individual afflicted with an acid-base disorder characterized by a baseline serum bicarbonate value of less than 22 mEq / l, the method comprising oral administration of a pharmaceutical composition, wherein thepharmaceutical composition given orally binds at least 5 mEq per day on average of a target species in the digestive system, said oral administration achieving a clinically significant increase in the serum bicarbonate value of at least 1 mEq / l from baseline within a treatment period not greater than 1 month, the target species being selected from the group consisting of protons, strong acids, and conjugate bases of strong acids.

3. A method of treating an individual afflicted with an acid-base disorder characterized by a baseline serum bicarbonate value of less than 22 mEq / l, the method comprising oral administration of a daily dose of a pharmaceutical composition containing a nonabsorbable composition;wherein said oral administration increases the individual's serum bicarbonate value from baseline to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 1 mEq / l; andwherein the treatment enables the increased serum bicarbonate value to be sustained over a prolonged period of at least one week, at least one month, at least two months, at least three months, at least six months, or at least one year.

4. The method of any preceding claim wherein the oral administration is as frequent as at least weekly, at least semi-weekly, or daily within the treatment period.

5. The method of any preceding claim wherein the acid-base disorder is characterized by a baseline serum bicarbonate value of less than 18 mEq / l.

6. The method of any preceding claim wherein the acid-base disorder is characterized by a baseline serum bicarbonate value of at least 12 mEq / l.

7. The method of any preceding claim wherein the acid-base disorder is characterized by a baseline serum bicarbonate value of at least 15 mEq / l.

8. The method of any preceding claim wherein the method increases the serum bicarbonate value from the baseline serum bicarbonate value to an increased serum bicarbonate value of at least 22 mEq / l but not in excess of 29 mEq / l.

9. The method of any preceding claim wherein the clinically significant increase is at least 3 mEq / l.

10. The method of any preceding claim wherein the clinically significant increase is achieved within a treatment period of 2 weeks.1 1 . The method of any preceding claim wherein, upon cessation of the treatment, the individual's serum bicarbonate value decreases by at least 2 mEq / l within 1 month of the cessation of treatment.

12. The method of any preceding claim wherein the baseline serum bicarbonate value is the mean value of at least two serum bicarbonate concentrations for serum samples drawn on different days.

13. The method of any preceding claim wherein the individual is being treated for chronic metabolic acidosis.

14. The method of any preceding claim wherein the daily dose has the capacity to remove at least 7.5 mEq, 15 mEq or 25 mEq of a target species as it transits the digestive system.

15. The method of any preceding claim wherein the daily dose is less than 40 g / day, less than 25 g / day, less than 15 g / day, or less than 10 g / day.

16. The method of any preceding claim wherein the pharmaceutical composition is a nonabsorbable composition comprising a population of particles having a median particle diameter size (volume distribution) of at least 3 microns.

17. The method of any preceding claim wherein the pharmaceutical composition is a nonabsorbable composition comprising a population of particles having a particle sizerange that is (i) large enough to avoid passive or active absorption through the Gl tract and (ii) small enough to not cause grittiness or unpleasant mouth feel when ingested as a powder, suspension, gel, and / or tablet.

18. The method of any preceding claim wherein the pharmaceutical composition is a nonabsorbable composition comprising a population of particles have a Swelling Ratio of less than 5 or less than 2.

19. The method of any preceding claim wherein the nonabsorbable composition has a theoretical binding capacity for the target species of at least about 3 mEq / g or at least about 10 mEq / g.

20. The method of any preceding claim wherein the theoretical binding capacity for the target species is the theoretical binding capacity as determined in a SGF assay.21 . The method of any preceding claim wherein the daily dose has the capacity to remove at least about 10 mEq / day, at least about 15 mEq / day, at least about 20 mEq / day, at least about25 mEq / day of the target species, or at least about 30 mEq / day of the target species.

22. The method of any preceding claim wherein the daily dose removes less than 50 mEq / day or less than 35 mEq / day of the target species.

23. The method of any preceding claim wherein the nonabsorbable composition is a cation exchange material comprising exchangeable cations selected from the group consisting of sodium, potassium, calcium, magnesium, and combinations thereof.

24. The method of any preceding claim wherein the nonabsorbable composition is a cation exchange material comprising exchangeable cations selected from the group consisting of sodium, potassium, and combinations thereof.

25. The method of any preceding claim wherein the nonabsorbable composition is a cation exchange material optionally containing exchangeable sodium ions provided, however, that the amount of the sodium ions in a daily dose is insufficient to increase the patient's serum sodium ion concentration to a value outside the range of 135 to 145 mEq / l.

26. The method of any preceding claim wherein the nonabsorbable composition is a cation exchange material containing exchangeable sodium ions and the composition contains less than 1 % by weight sodium.

27. The method of any preceding claim wherein the nonabsorbable composition is an anion exchange material having the capacity to induce an increase in the individual's serum bicarbonate value, at least in part, by delivering a physiologically significant amount of hydroxide, carbonate, citrate or other bicarbonate equivalent, or a combination thereof.

28. The method of any preceding claim wherein the nonabsorbable composition is an anion exchange material comprising at least 1 mEq / g of an anion selected from the group consisting of hydroxide, carbonate, citrate or other bicarbonate equivalent anion, or a combination thereof.

29. The method of any of claims 1 to 27 wherein the nonabsorbable composition is an anion exchange material comprising less than 1 mEq / g of an anion selected from the group consisting of hydroxide, carbonate, citrate or other bicarbonate equivalent anion.

30. The method of any preceding claim wherein the nonabsorbable composition is an amphoteric ion exchange resin.31 . The method of any preceding claim wherein the target species comprises protons.

32. The method of any preceding claim wherein the target species comprises the conjugate base of a strong acid selected from the group consisting of chloride, bisulfate and sulfate ions.

33. The method of any preceding claim wherein the target species comprises chloride ions.

34. The method of any preceding claim wherein the target species comprises a strong acid.

35. The method of any preceding claim wherein the target species comprises hydrochloric acid.

36. The method of any preceding claim wherein the nonabsorbable composition is characterized by a chloride ion binding capacity of at least 1 mEq / g in a SIB assay.

37. The method of any preceding claim wherein the nonabsorbable composition is characterized by a chloride ion binding capacity of at least 1 .5 mEq / g in a SIB assay.

38. The method of any preceding claim wherein the nonabsorbable composition is characterized by a chloride ion binding capacity of at least 2 mEq / g in a SIB assay.

39. The method of any preceding claim wherein the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 0.25: 1 , respectively.

40. The method of any preceding claim wherein the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 0.5:1 , respectively.41 . The method of any preceding claim wherein the ratio of the amount of bound chloride to bound phosphate in a SIB assay is at least 1 : 1 , respectively.

42. The method of any preceding claim wherein the nonabsorbable composition is a neutral composition having the capacity to bind both protons and anions.

43. The method of any preceding claim wherein the nonabsorbable composition is a neutral composition having the capacity to bind both protons and anions selected from the group consisting of polymers functionalized with propylene oxide, polymersfunctionalized with Michael acceptors, expanded porphyrins, covalent organic frameworks, and polymers containing amine and / or phosphine functional groups.

44. The method of any preceding claim wherein the nonabsorbable composition (i) removes more chloride ions than bicarbonate equivalent anions (ii) removes more chloride ions than phosphate anions, and (iii) remove more chloride ions than the conjugate bases of bile and fatty acids.

45. The method of any preceding claim wherein the treatment with thenonabsorbable composition does not have a clinically significant impact upon the serum or colon levels of a metabolically relevant species.

46. The method of any preceding claim wherein the treatment with thenonabsorbable composition does not have a clinically significant impact upon the serum or colon levels of a metabolically relevant cationic species.

47. The method of any preceding claim wherein the treatment with thenonabsorbable composition does not have a clinically significant impact upon the serum or colon levels of a metabolically relevant anionic species.

48. The method of any preceding claim wherein the treatment with thenonabsorbable composition does not have a clinically significant impact upon the serum potassium levels of a statistically significant number of individuals.

49. The method of any preceding claim wherein the treatment with the nonabsorbable composition does not have a clinically significant impact upon the serum phosphate levels of a statistically significant number of individuals.

50. The method of any preceding claim wherein the treatment with thenonabsorbable composition does not have a clinically significant impact upon the serum low density lipoprotein (LDL) levels of a statistically significant number of individuals.51 . The method of any preceding claim wherein the pharmaceutical composition is a nonabsorbable composition comprising a proton-binding, crosslinked amine polymer comprising the residue of an amine corresponding to Formula 1 :NR3Formula 1wherein R-i , R2and R3are independently hydrogen, hydrocarbyl, or substituted hydrocarbyl provided, however, at least one of R-i , R2and R3is other than hydrogen.

52. The method of any preceding claim wherein the pharmaceutical composition is a nonabsorbable composition comprising a proton-binding, crosslinked amine polymer comprising the residue of an amine corresponding to Formula 1 :NR3Formula 1 wherein R-i , R2and R3are independently hydrogen, hydrocarbyl, or substituted hydrocarbyl provided, however, at least one of R-i , R2and R3is other than hydrogen, and thecrosslinked amine polymer has (i) an equilibrium proton binding capacity of at least 5 mmol / g and a chloride ion binding capacity of at least 5 mmol / g in an aqueous simulated gastric fluid buffer ("SGF") containing 35 mM NaCI and 63 mM HCI at pH 1 .2 and 37 °C, and (ii) an equilibrium swelling ratio in deionized water of about 2 or less.

53. The method of any preceding claim wherein the pharmaceutical composition is a nonabsorbable composition comprising the residue of an amine corresponding toFormula 1 :NR3Formula 1 wherein R-i , R2and R3are independently hydrogen, hydrocarbyl, substituted hydrocarbyl provided, however, at least one of R-i, R2and R3is other than hydrogen, the crosslinked amine polymer has an equilibrium swelling ratio in deionized water of about 5 or less, and the crosslinked amine polymer binds a molar ratio of chloride ions to interfering ions of at least 0.35: 1 , respectively, in an interfering ion buffer at 37 °C wherein the interfering ions are phosphate ions and the interfering ion buffer is a buffered solution at pH 5.5 of 36mM chloride and 20mM phosphate.

54. The method of any preceding claim wherein the nonabsorbable composition has an equilibrium chloride binding capacity of at least 10 mmol / g in an aqueous simulated gastric fluid buffer ("SGF") containing 35 mM NaCI and 63 mM HCI at pH 1 .2 and 37 °C.

55. The method of any preceding claim wherein the crosslinked amine polymer comprises the residue of an amine corresponding to Formula 1 a and the crosslinked amine polymer is prepared by radical polymerization of an amine corresponding to Formula 1 a:R4\ ^CH2CH=CH2NR5Formula 1 awherein R4and R5are independently hydrogen, hydrocarbyl, or substituted hydrocarbyl.

56. The method of any preceding claim wherein the pharmaceutical composition is a nonabsorbable composition comprising a crosslinked amine polymer containing the residue of an amine corresponding to Formula 1 b and the crosslinked amine polymer is prepared by substitution polymerization of the amine corresponding to Formula 1 b with a polyfunctional crosslinker:Fromula 1 bwherein R4and R5are independently hydrogen, hydrocarbyl, or substituted hydrocarbyl, R6is aliphatic and R6i and R62 are independently hydrogen, aliphatic, or heteroaliphatic.

56. The method of any preceding claim wherein the daily dose is administered once-a-day (QD).

57. The method of any preceding claim wherein the the ealed container comprises a multi-layer laminate of an inner contact layer, an outer layer; and a barrier layer disposed between the contact layer and outer layer.

58. A composition for use in a method of treating metabolic acidosis in an adult human patient, wherein (i) the method of treatment is as defined in any preceding claim or (ii) the composition is as defined in any preceding claim.

59. A composition for use in a method of treating metabolic acidosis in an adult human patient wherein in said treatment 0.1 - 12 g of said composition is administered to the patient per day, said composition being a nonabsorbable composition having the capacity to remove protons from the patient, wherein the nonabsorbable composition is characterized by a chloride ion binding capacity of at least 2.5 mEq / g in a Simulated Small Intestine Inorganic Buffer ("SIB") assay.

60. A composition for use in a method of treating metabolic acidosis in an adult human patient, said patient having a serum bicarbonate level of less than 20 mEq / L prior to treatment, said composition being a nonabsorbable composition having the capacity to remove protons from the patient.61 . A composition for use in a method of treating metabolic acidosis in an adult human patient by increasing that patient's serum bicarbonate value by at least 1 mEq / L over 15 days of treatment, said composition being a nonabsorbable composition having the capacity to remove protons from the patient.

62. A method of increasing serum bicarbonate levels in an individual afflicted with an acid-base disorder, the method comprising oral administration of a pharmaceutical composition to increase the individual's serum bicarbonate levels wherein:(i) the pharmaceutical composition binds a target species in the individual's digestive system when given orally, the target species being selected from the group consisting of protons, strong acids, and conjugate bases of strong acids and(ii) the pharmaceutical composition increases the serum bicarbonate level by at least 1 mEq / l in a placebo controlled study, said increase being the difference between the cohort average serum bicarbonate level in a first cohort at the end of the study, relative to the cohort average serum bicarbonate level in a second cohort at the end of the study, wherein the first cohort's subjects receive the pharmaceutical composition and the second cohort's subjects receive a placebo, wherein the first and second cohorts each comprise at least 25 subjects, each cohort is prescribed the same diet during the study and the study lasts at least two weeks.

63. The method of claim 61 wherein the first cohort receives a daily dose of the pharmaceutical composition that does not exceed 10 g / day.

64. The method of any of claims 62 to 63 wherein the potential renal acid load (PRAL value) of the diet is, on average, 0.82 mEq / d).

65. The method of any of claims 62 to 64 wherein eligible subjects for the study have chronic kidney disease (CKD Stage 3 - 4; eGFR 20 - <60 mL / min / 1.73m2) and a baseline serum bicarbonate value at the start of the study between 12 and 20 mEq / L.

66. The method of any of claims 62 to 65 wherein the pharmaceutical composition increases the serum bicarbonate level by at least 3 mEq / l in the placebo controlled study.

67. The method of any of claims 62 to 66 wherein the target species is a strong acid.

68. The method of any of claims 62 to 67 wherein the pharmaceutical composition is not absorbed when inqested.

69. A method of treating an individual afflicted with an acid-base disorder characterized by a baseline serum bicarbonate value of less than 22 mEq / l, the method comprising oral administration of a daily dose of a pharmaceutical composition containing a nonabsorbable composition; wherein said oral administration increases the individual's serum bicarbonate value from baseline to an increased serum bicarbonate value that exceeds the baseline serum bicarbonate value by at least 1 mEq / l; andwherein the treatment enables the increased serum bicarbonate value to be sustained over a prolonged period of at least one week, at least one month, at least two months, at least three months, at least six months, or at least one year.

70. The method of claim 69 wherein the treatment decreases the individual's anion gap by at least 1 mEq / L.

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