Phosphate binding agents and their use for treatment of hyperphosphatemia

Abstract

The present invention relates to a phosphate binder and its use for the treatment of hyperphosphatemia. The phosphate binding agent at least comprises at least one guanidino-containing cross-linked polymer or a pharmaceutically acceptable salt thereof, the guanidino-containing cross-linked polymer is derived from polyallylamine or a pharmaceutically acceptable salt thereof, the guanidino-containing cross-linked polymer comprises a guanidino structural unit and a cross-linked structural unit, and the cross-linked structural unit is derived from polyallylamine or a pharmaceutically acceptable salt thereof. The guanidino structural unit and the cross-linked structural unit are respectively represented by formulae (1) and (2): # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the field of medicine and relates to a novel phosphate binder and its use for the treatment of hyperphosphatemia. Background Art

[0002] Hyperphosphatemia is a common complication in patients with end-stage renal disease. Due to the decline in renal function of patients, the ability of the kidneys to regulate phosphorus is reduced, resulting in increased blood phosphorus, which in turn causes a series of changes in the levels of calcium, phosphorus, parathyroid hormone and vitamin D. Hyperphosphatemia is an independent risk factor for the progression of kidney disease, secondary hyperparathyroidism, cardiovascular events and all-cause death in patients with chronic kidney disease, seriously affecting the quality of life and physical and mental health of patients.

[0003] Currently, the conventional treatment methods for reducing serum phosphorus mainly focus on the 3D principle, including dialysis, diet control and drug control. High-molecular polymers with phosphate-binding ability are a common type of drug used to treat hyperphosphatemia, and the representative drug is sevelamer. This type of phosphate binder hardly dissolves in the blood, so there is no potential cytotoxicity. At the same time, this type of phosphate binder does not contain calcium ions and will not increase the risk of organ calcification; moreover, it does not contain iron ions and will not increase the risk of iron overload.

[0004] Known phosphate binders, including sevelamer hydrochloride and sevelamer carbonate, have the chemical structures shown in the following formulas (I) and (II):

[0005]

[0006] Known sevelamer reduces the phosphorus content in the blood by binding through the ionic interaction between amino groups and phosphates. However, the binding effect of this known phosphate binder on phosphate ions in the body, especially in the digestive tract, cannot meet the increasing medical needs. Therefore, there is always a need for a phosphate binder with better efficacy. Summary of the Invention

[0007] An object of the present invention is to provide a novel phosphate binder to replace the existing sevelamer, thereby providing more options for the treatment of hyperphosphatemia.

[0008] A further object of the present invention is to provide a novel phosphate binder that has a better binding effect on phosphate ions in the body, especially in the digestive tract, compared with the existing sevelamer.

[0009] Through a large number of experimental studies, the inventors of the present application found that the guanidine group (-NH-C(=NH)-NH2) can form stronger ionic interactions with phosphates. Therefore, it is speculated that cross-linked polymers containing such functional groups have stronger phosphate-binding abilities. For this reason, the inventors of the present application designed a novel guanidine group-containing cross-linked polymer or a pharmaceutically acceptable salt thereof suitable for use as a phosphate binder.

[0010] In a first aspect, the present invention provides a phosphate binder comprising at least one guanidine group-containing cross-linked polymer or a pharmaceutically acceptable salt thereof, wherein the guanidine group-containing cross-linked polymer is derived from polyallylamine or a pharmaceutically acceptable salt thereof, and wherein the guanidine group-containing cross-linked polymer comprises a guanidine structural unit and a cross-linked structural unit, and the guanidine structural unit and the cross-linked structural unit are represented by the following formulas (1) and (2), respectively:

[0011]

[0012] The term "pharmaceutically acceptable" means that the corresponding compound, carrier or molecule is suitable for administration to humans. Preferably, the term means that it is certified by a regulatory agency such as CFDA (China), EMEA (Europe), FDA (USA) or any other national regulatory agency for use in mammals, preferably humans.

[0013] The pharmaceutically acceptable salts include acid addition salts and base addition salts thereof. Suitable acid addition salts are formed from acids that form non-toxic salts. Examples thereof include, but are not limited to: acetate, adipate, aspartate, benzoate, benzenesulfonate, bicarbonate / carbonate, bisulfate / sulfate, borate, camphorsulfonate, citrate, cyclohexanesulfamate, ethanedisulfonate, formate, fumarate, glucoheptonate, gluconate, glucuronate, hexafluorophosphate, 2-(4-hydroxybenzyl)benzoate, hydrochloride, hydrobromide, hydroiodide, 2-hydroxyethanesulfonate, lactate, malate, maleate, malonate, mesylate, methylsulfate, naphthoate, 2-naphthalenesulfonate, nicotinate, nitrate, orotate, oxalate, palmitate, phosphate / hydrogenphosphate / dihydrogenphosphate, pyroglutamate, glucarate, stearate, salicylate, tannate, tartrate, tosylate, and trifluoroacetate. Suitable base addition salts are formed from bases that form non-toxic salts. Examples thereof include, but are not limited to: aluminum, arginine, calcium, choline, diethylamine, diethanolamine, glycine, lysine, magnesium, meglumine, ethanolamine, potassium, sodium, tromethamine, and zinc salts. Hemisalts of acids and bases, such as hemisulfates and hemicalcium salts, can also be formed. For a review of suitable salts, see Handbook of Pharmaceutical Salts: Properties, Selection and Use by Stahl and Wermuth (Wiley-VCH, 2002). Methods for preparing the pharmaceutically acceptable salts described herein are known to those skilled in the art.

[0014] In an embodiment according to the present invention, the guanidine group-containing crosslinked polymer is derived from polyallylamine or a pharmaceutically acceptable salt thereof. The polyallylamine or a pharmaceutically acceptable salt thereof can be any commercially available polyallylamine or a pharmaceutically acceptable salt thereof known in the art. In some embodiments according to the present invention, the polyallylamine has a weight-average molecular weight of 3,000 to 18,000, and the weight-average molecular weight is determined by GPC.

[0015] In an embodiment according to the present invention, the guanidine group-containing crosslinked polymer comprises a guanidine group structural unit and a crosslinked structural unit, wherein the guanidine group structural unit and the crosslinked structural unit are respectively represented by the following formulas (1) and (2):

[0016]

[0017] In some embodiments of the present invention, the guanidine group-containing crosslinked polymer may further comprise an amino group structural unit, and the amino group structural unit is represented by the following formula (3):

[0018]

[0019] As shown in the above structure, the guanidine group-containing crosslinked polymer according to the present invention not only has a crosslinked structural unit similar to that of sevelamer and an optional amino group structural unit, but also additionally has a guanidine group structural unit. It is the presence of the guanidine group structural unit that endows the guanidine group-containing crosslinked polymer according to the embodiments of the present invention with a stronger phosphate binding ability. In vitro and in vivo phosphate binding tests show that the guanidine group-containing crosslinked polymer according to the embodiments of the present invention can effectively bind phosphate; under the same conditions, the guanidine group-containing crosslinked polymer according to the embodiments of the present invention has better in vivo activity than sevelamer. Therefore, the guanidine group-containing crosslinked polymer of the present invention has the potential to treat hyperphosphatemia.

[0020] The synthesis of the guanidine group-containing crosslinked polymer according to the embodiments of the present application can be divided into two steps. First, based on polyallylamine (PA), some amino groups are modified with a guanidinating reagent to obtain an allylamine allylguanidine copolymer intermediate (PA-PAG) containing a guanidine group structural unit; then, the amino groups of the allylamine allylguanidine copolymer (PA-PAG) are crosslinked with epichlorohydrin to obtain a spatially structured guanidine group-containing crosslinked polymer.

[0021] A guanidine group-containing polymer can be prepared by reacting an amino group-containing polymer precursor with a guanidinating reagent. Although all the amino groups of the amino group-containing polymer can react with the guanidinating reagent, usually some unreacted amino groups from the amino group-containing polymer precursor are retained in the guanidine group-containing polymer. Generally, at least 0.1 mol%, at least 0.5 mol%, at least 1 mol%, at least 2 mol%, at least 10 mol%, at least 20 mol% or at least 50 mol% of the amino groups in the amino group-containing polymer precursor react with the guanidinating reagent. At most 100 mol%, at most 90 mol%, at most 80 mol% or at most 60 mol% of the amino groups can react with the guanidinating reagent. For example, the guanidinating reagent can be used in an amount sufficient to functionalize 0.1 mol% to 100 mol%, 0.5 mol% to 90 mol%, 1 mol% to 90 mol%, 1 mol% to 80 mol%, 1 mol% to 60 mol%, 2 mol% to 50 mol%, 2 mol% to 25 mol%, or 2 mol% to 10 mol%, 5 mol% to 80 mol%, 5 mol% to 60 mol%, 5 mol% to 50 mol%, 5 mol% to 25 mol%, or 5 mol% to 10 mol%, 10 mol% to 80 mol%, 10 mol% to 60 mol%, 10 mol% to 50 mol% or 10 mol% to 25 mol% of the amino groups in the amino group-containing polymer.

[0022] Known guanidinating reagents for reaction with amino-containing polymer precursors include, but are not limited to, cyanamide; O-alkyl isourea salts such as O-methyl isourea sulfate, O-methyl isourea bisulfate, O-methyl isourea acetate, O-ethyl isourea bisulfate, and O-ethyl isourea hydrochloride; S-alkyl isourea salts such as S-methyl isourea sulfate, S-methyl isourea bisulfate, S-methyl isourea acetate, S-ethyl isourea bisulfate, and S-ethyl isourea hydrochloride; chloromethylamidine hydrochloride; 1-amidino-1,2,4-triazole hydrochloride; 3,5-dimethylpyrazole-1-carboxamidine nitrate; pyrazole-1-carboxamidine hydrochloride; N-amidinopyrazole-1-carboxamidine hydrochloride; and carbodiimides such as dicyclohexylcarbodiimide, N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide, and diisopropylcarbodiimide. The amino-containing polymer can also be acylated with guanidine-functionalized carboxylic acids such as guanidinoacetic acid and 4-guanidinobutyric acid in the presence of an activating reagent such as EDC (N-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride) or EEDQ (2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline). Additionally, chloroacetamidine hydrazone can be used to prepare guanidine-containing polymers by an alkylation reaction as described in U.S. Patent 5,712,027 (Ali et al.). In a preferred embodiment according to the present invention, the guanidinating reagent is selected from S-methylisothiourea hemisulfate and 1H-pyrazole-1-carboxamidine hydrochloride.

[0023] The guanidine-containing polymer intermediate obtained above can be crosslinked. The guanidine-containing polymer can be crosslinked by reacting epichlorohydrin with some or all of the remaining amino groups in the guanidine-containing polymer intermediate. In some embodiments according to the present invention, some of the remaining amino groups in the guanidine-containing polymer intermediate react with epichlorohydrin, thereby crosslinking the guanidine-containing polymer. In some embodiments according to the present invention, all of the remaining amino groups in the guanidine-containing polymer intermediate react with epichlorohydrin, thereby achieving saturated crosslinking of the guanidine-containing polymer.

[0024] Therefore, in some preferred embodiments of the present invention, in the guanidine-containing crosslinked polymer contained in the phosphate binder, based on the total molar amount of the amino structural unit, the guanidine structural unit, and the crosslinked structural unit, the molar content of the guanidine structural unit is in the range of 5 mol% to 65 mol%, preferably in the range of 10 mol% to 25 mol%; the molar content of the crosslinked structural unit is in the range of 6 mol% to 95 mol%, preferably in the range of 10 mol% to 20 mol%; and the molar content of the amino structural unit is in the range of 0 to 77 mol%, preferably in the range of 50 mol% to 70 mol%.

[0025] As an exemplary illustration, the process of preparing the guanidine group-containing crosslinked polymer according to the embodiments of the present application by successively undergoing guanidination and crosslinking on the basis of polyallylamine hydrochloride is given as follows.

[0026] Preparation of allylamine allylguanidine copolymer (PA-PAG)

[0027] Guanidination method 1:

[0028] React polyallylamine hydrochloride (PA) with S-methylisothiourea hemisulfate, and after post-treatment, obtain the allylamine allylguanidine copolymer intermediate (PA-PAG).

[0029]

[0030] Guanidination method 2:

[0031] React polyallylamine hydrochloride (PA) with 1H-pyrazole-1-carboxamidine hydrochloride, and after post-treatment, obtain the allylamine allylguanidine copolymer intermediate (PA-PAG).

[0032]

[0033] Preparation of guanidine group-containing crosslinked polymer

[0034] Crosslinking method

[0035] Crosslink the above allylamine allylguanidine copolymer intermediate (PA-PAG) with epichlorohydrin, and after post-treatment, obtain the desired guanidine group-containing crosslinked polymer.

[0036]

[0037] In some preferred embodiments of the present invention, the pharmaceutically acceptable salt includes hydrochloride or carbonate.

[0038] In some preferred embodiments of the present invention, the phosphate binder is a powdery solid.

[0039] Another aspect of the present invention provides a preparation method for preparing a phosphate binder, the method comprising the following steps:

[0040] a) Provide the polyallylamine or its pharmaceutically acceptable salt as a polymer substrate;

[0041] b) React the polymer substrate with a guanidination reagent to form a guanidine group-containing polymer intermediate;

[0042] c) Crosslink the guanidine group-containing polymer intermediate with epichlorohydrin to form a guanidine group-containing crosslinked polymer.

[0043] In some embodiments according to the present invention, the pharmaceutically acceptable salts of the guanidine group-containing crosslinked polymer can also be formed by an acid exchange method. As an illustrative example, the carbonate of the guanidine group-containing crosslinked polymer can be formed by interacting the hydrochloride salt of the guanidine group-containing crosslinked polymer with a carbonate donor such as an alkali metal carbonate (e.g., sodium carbonate).

[0044] In a third aspect, the present invention provides a pharmaceutical composition comprising the phosphate binder of the present application as described above, and one or more pharmaceutically acceptable carriers, adjuvants or excipients.

[0045] The pharmaceutical composition of the present invention can be formulated into dosage forms suitable for oral administration, topical administration (including but not limited to external application, spraying, etc.), parenteral administration (including subcutaneous, intramuscular, dermal and intravenous), bronchial administration or nasal administration as required. Among them, preferably, the pharmaceutical composition of the present invention is formulated into a dosage form (preparation) suitable for oral or topical administration. More preferably, the pharmaceutical composition of the present invention is formulated into a dosage form (preparation) suitable for oral administration.

[0046] If a solid carrier is used, the preparation can be in the form of tablets, placed in hard gel capsules in powder or granule form, or in the form of lozenges or pastilles. Solid carriers can include conventional excipients such as binders, fillers, tablet lubricants, disintegrants, wetting agents, and the like. If desired, the tablets can be film-coated by conventional techniques. If a liquid carrier is used, the preparation can be in the form of syrup, emulsion, ointment, soft gel capsule, a sterile carrier for injection, an aqueous or non-aqueous liquid suspension, or a dry product that is reconstituted with water or other suitable carrier before use. Liquid preparations can contain conventional additives such as suspending agents, emulsifying agents, wetting agents, non-aqueous carriers (including edible oils), preservatives, and flavoring and / or coloring agents. For parenteral administration, generally the carrier consists of at least mostly sterile water, but saline solutions, glucose solutions, etc. can also be used. Injectable suspensions can also be used, in which case conventional suspending agents can be used. Conventional preservatives, buffering agents, etc. can also be added to parenteral dosage forms. The pharmaceutical composition is prepared by conventional techniques suitable for the desired preparation containing an appropriate amount of the active ingredient (i.e., the phosphate binder of the present invention).

[0047] Compositions suitable for parenteral injection can include physiologically acceptable sterile aqueous or non-aqueous solutions, dispersions, suspensions or emulsions and sterile powders for sterile injectable solutions or dispersions. Examples of suitable aqueous and non-aqueous carriers, diluents, solvents include water, ethanol, polyols (propylene glycol, polyethylene glycol, glycerol, etc.), suitable mixtures thereof, vegetable oils (e.g., olive oil) and injectable organic esters (e.g., ethyl oleate).

[0048] These compositions may also contain various excipients, for example, preservatives, wetting agents, emulsifying agents, and dispersing agents. The inhibition of the action on microorganisms can be ensured by various antibacterial and antifungal agents (for example, parabens, chlorobutanol, phenol, sorbic acid, etc.). Isotonic agents, such as sugars, sodium chloride, etc., may also be included. The absorption of injectable pharmaceutical dosage forms can be prolonged by using delayed absorption reagents (for example, aluminum monostearate and gels).

[0049] Solid dosage forms for oral use include capsules, tablets, pills, powders, and granules. In such solid dosage forms, the active compound is admixed with at least one inert excipient (or carrier) (such as sodium citrate or calcium phosphate dibasic), and may also include: (a) fillers or bulking agents (such as starch, lactose, sucrose, glucose, mannitol, and silicic acid); (b) binders (such as carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone, sucrose, and gum arabic); (c) humectants (such as glycerol); (d) disintegrants (such as agar-agar, calcium carbonate, potato or tapioca starch, alginic acid, certain synthetic silicates, sodium carbonate); (e) solution retarders (such as paraffin); (f) absorption promoters (such as quaternary ammonium compounds); (g) wetting agents (such as cetyl alcohol and glyceryl monostearate); (h) adsorbents (such as kaolin and bentonite); and (i) lubricants (such as talc, calcium stearate, magnesium stearate, solid polyethylene glycol, sodium lauryl sulfate) or mixtures thereof.

[0050] Solid compositions of a similar type may also be used as fillers in soft and hard gelatin capsules using, for example, lactose and high molecular weight polyethylene glycols, etc., as excipients.

[0051] Solid dosage forms (such as tablets, dragees, capsules, pills, and granules) can be prepared with coatings and shells (such as enteric coatings and others known in the art). They may contain opacifying agents, and they may also be compositions that release the active compound or various active compounds in a delayed manner in a certain part of the intestine. Examples of embedding compositions that can be used are polymeric substances and waxes. The active ingredient may also be in microencapsulated form and, if appropriate, may have one or more of the above excipients.

[0052] Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, dispersions, syrups, and elixirs. In addition to the active compound, liquid dosage forms may contain inert diluents commonly used in the art (e.g., water or other solvents), solubilizing agents, and emulsifying agents (e.g., ethanol, isopropanol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3 - butanediol, dimethylformamide), oils (specifically, cottonseed oil, peanut oil, corn oil, olive oil, castor oil, sesame oil), glycerol, tetrahydrofurfuryl alcohol, polyethylene glycol, and fatty acid esters of sorbitan or mixtures of these substances, etc.

[0053] In addition to these inert diluents, the composition may further include, for example, wetting agents, emulsifying and suspending agents, perfuming agents, flavoring agents, and odoriferous substances.

[0054] In addition to the active compound, suspensions may contain suspending agents such as ethoxylated isostearyl alcohols, polyoxyethylene sorbitol, sorbitan esters, microcrystalline cellulose, aluminum hydroxide, bentonite, agar - agar, and tragacanth or mixtures of these substances, etc.

[0055] The amount of the phosphate binder in the pharmaceutical composition and dosage form can be appropriately determined by those skilled in the art according to needs. For example, the phosphate binder can be present in a therapeutically effective amount in the pharmaceutical composition or dosage form.

[0056] The fourth aspect of the present invention provides the use of the phosphate binder according to the first aspect of the present invention or the phosphate binder prepared by the method according to the second aspect of the present invention in the manufacture of a medicament for treating hyperphosphatemia in a subject in need thereof.

[0057] Hyperphosphatemia refers to a pathological state in which the concentration of phosphate (phosphorus) in the blood is abnormally elevated. According to the etiology and pathogenesis, hyperphosphatemia includes but is not limited to:

[0058] · Chronic kidney disease (CKD): When renal function declines (especially when GFR < 30 mL / min / 1.73m 2 ), the kidneys are unable to effectively excrete phosphorus. It is often accompanied by secondary hyperparathyroidism (elevated PTH).

[0059] · Acute kidney injury (AKI): A sharp decline in renal function in a short period, resulting in phosphorus retention.

[0060] · Hypoparathyroidism: Insufficient secretion of parathyroid hormone (PTH), reducing the excretion of phosphorus by the renal tubules.

[0061] · Pseudohypoparathyroidism: A genetic disease in which the target organs are resistant to PTH, resulting in manifestations similar to hypoparathyroidism.

[0062] ·Excessive exogenous intake: Excessive intake of phosphorus-containing foods (such as dairy products, processed foods), phosphorus-containing drugs (such as phosphate laxatives, certain vitamin D supplements).

[0063] ·Iatrogenic overdose: Excessive intravenous phosphorus supplementation, phosphorus-containing enemas, etc.

[0064] ·Excessive vitamin D: Vitamin D promotes intestinal phosphorus absorption, and excessive intake can lead to elevated blood phosphorus.

[0065] ·Tumor lysis syndrome (TLS): Chemotherapy or radiotherapy causes a large number of tumor cells to die, and intracellular phosphorus is released into the blood.

[0066] ·Rhabdomyolysis: Muscle damage (such as trauma, drugs, strenuous exercise) causes muscle cell destruction and releases phosphorus.

[0067] ·Metabolic acidosis: During acidosis, cell metabolism is abnormal, promoting the transfer of phosphorus from inside the cell to outside the cell.

[0068] ·Hemolysis: After red blood cells are destroyed, intracellular phosphorus is released.

[0069] The fifth aspect of the present invention provides a method for treating hyperphosphatemia in a subject in need, the method comprising administering to the subject a therapeutically effective amount of a phosphate binder according to the first aspect of the present invention or a phosphate binder prepared by the method according to the second aspect of the present invention.

[0070] The subject is preferably a mammal, more preferably a human patient. The administration route can be oral, topical (including but not limited to external application, spraying, etc.), parenteral (including subcutaneous, intramuscular, dermal and intravenous) administration, bronchial administration or nasal administration, etc.

[0071] Unexpectedly, the guanidine group-containing crosslinked polymer of the present invention can significantly reduce the concentration of phosphate in phosphate buffer in vitro. Moreover, oral administration of the guanidine group-containing crosslinked polymer of the present invention can reduce the urinary phosphorus level in rats fed a high-phosphorus diet, and its oral in vivo activity is much higher than that of sevelamer.

[0072] The following further illustrates and describes the present application with specific examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 Shows the effect of oral administration of the guanidine group-containing crosslinked polymer according to Example 9 on urinary phosphorus in rats. EXAMPLES

[0074] The examples set forth hereinbelow are for illustrative purposes only, to exemplify various aspects and embodiments of the present invention and are not intended to limit in any way the scope of the present invention claimed.

[0075] Unless otherwise stated, all reactants were obtained commercially. The instruments and equipment used in the synthesis experiments and product analysis and testing were all conventional instruments and equipment commonly used in organic synthesis.

[0076] Example 1

[0077] According to the literature CN103159880B, the positive control drug sevelamer hydrochloride was prepared. Its structural characteristics were as follows: the weight-average molecular weight of the raw material polyallylamine was 17,000; it did not contain guanidine units; the cross-linking method was epichlorohydrin cross-linking; the molar ratio of the cross-linking units was 18%; the salt form was hydrochloride.

[0078] At room temperature, polyallylamine hydrochloride (30 g, weight-average molecular weight 17,000) was dissolved in water (60 mL). After complete dissolution, the pH of the system was adjusted to 11 using an aqueous sodium hydroxide solution (10 N). At room temperature, span 85 (1.38 g) was added to toluene (240 mL), and stirred until completely dispersed and uniform. At room temperature, the toluene solution of span 85 was added to the aqueous solution of polyallylamine hydrochloride, while maintaining stirring, epichlorohydrin (2.67 g) was added. After addition, stirring was continued and the reaction was carried out at room temperature for 16 hours. The reaction solution was filtered, the crude product was slurried with water and filtered, and this was repeated twice. Then the crude product was slurried with isopropanol and filtered, and this was repeated twice. After the wet filter cake was dried under reduced pressure at 70 °C, it was ground with a pulverizer to obtain Example 1 (23.1 g), which was a white powdery solid.

[0079] Elemental analysis:

[0080] Element Nitrogen Carbon Hydrogen Sulfur Oxygen Content (%) 16.32 45.26 9.83 N.D. 11.73

[0081] Note: N.D. indicates not detected.

[0082] Example 2

[0083] The structure of Example 2 was shown as General Formula I, and its characteristics were as follows: the weight-average molecular weight of the raw material polyallylamine was 18,000; the guanidinylation reagent was S-methylisothiourea hemisulfate, and the molar ratio of the guanidine units was 5%; the cross-linking method was epichlorohydrin cross-linking, and the cross-linking agent was in excess; the molar ratio of the cross-linking units was 95%; the salt form was hydrochloride.

[0084] At room temperature, polyallylamine hydrochloride (10 g, weight-average molecular weight 18,000) was dissolved in water (100 mL), S-methylisothiourea hemisulfate (0.75 g) was added, sodium bicarbonate (0.5 g) was added, and the reaction was carried out at 50 °C for 16 hours. HPLC was used to monitor the complete consumption of S-methylisothiourea hemisulfate, and the pH of the system was adjusted to 7 using hydrochloric acid (6 N). Methanol (100 mL) was added dropwise to the reaction solution under stirring to form a spongy solid. The reaction solution was filtered, and the solid was washed twice with water. After drying the solid under reduced pressure at 70 °C, it was ground with a pulverizer to obtain Example 2A (17.7 g), which was a white solid.

[0085] At room temperature, Example 2A (2.0 g) was added to water (6 mL), and the pH of the system was adjusted to 11 using an aqueous sodium hydroxide solution (10 N). At room temperature, Span 85 (86 mg) was added to toluene (16 mL), and the mixture was stirred until completely dispersed and homogeneous. At room temperature, the toluene solution of Span 85 was added to the aqueous solution of Example 2A, and stirring was maintained. Epichlorohydrin (2.77 g) was added, and after addition, the mixture was stirred and reacted at room temperature for 16 hours. The reaction solution was filtered, and the crude product was slurried with water and filtered, and this was repeated twice. Then the crude product was slurried with isopropanol and filtered, and this was repeated twice. After drying the wet filter cake under reduced pressure at 70 °C, it was ground with a pulverizer to obtain Example 2 (1.8 g), which was a powdery white solid.

[0086] Example 3

[0087] The structure of Example 3 is shown in General Formula I, and its characteristics are as follows: the weight-average molecular weight of the starting polyallylamine is 18,000; the guanidinylation reagent is S-methylisothiourea hemisulfate, and the molar ratio of the guanidine unit is 15%; the crosslinking method is epichlorohydrin crosslinking, and the crosslinking agent is in excess; the molar ratio of the crosslinking unit is 85%; the salt form is hydrochloride.

[0088] At room temperature, polyallylamine hydrochloride (70 g, weight-average molecular weight 18,000) was dissolved in water (700 mL), S-methylisothiourea hemisulfate (15.62 g) was added, sodium bicarbonate (166.6 g) was added, and the reaction was carried out at 50 °C for 40 hours. HPLC was used to monitor the complete consumption of S-methylisothiourea hemisulfate, and the pH of the system was adjusted to 7 using hydrochloric acid (6 N). Methanol (700 mL) was added dropwise to the reaction solution under stirring to form a translucent gel. The gel was centrifuged and collected, and after drying under reduced pressure at 70 °C, it was ground with a pulverizer to obtain Example 3A (44.2 g), which was a white solid.

[0089] At room temperature, add Example 3A (22.1 g) to water (66 mL), and adjust the pH of the system to 11 using an aqueous sodium hydroxide solution (10 N). At room temperature, add Span 85 (0.86 g) to toluene (177 mL), and stir to completely disperse and homogenize. At room temperature, add the toluene solution of Span 85 to the aqueous solution of Example 3A, maintain the stirring state, add epichlorohydrin (23.61 g), and after addition, maintain stirring and react at room temperature for 16 hours. Filter the reaction solution, slurry the crude product with water and filter, repeat twice, then slurry the crude product with isopropanol and filter, repeat twice. After drying the wet filter cake under reduced pressure at 70 °C, grind it with a pulverizer to obtain ANDP3 (27.5 g), which is a powdery white solid.

[0090] Example 4

[0091] The structure of Example 4 is shown in General Formula I, and its characteristics are as follows: the weight-average molecular weight of the raw material polyallylamine is 18,000; the guanidinylation reagent is S-methylisothiourea hemisulfate, and the molar ratio of the guanidine unit is 25%; the cross-linking method is epichlorohydrin cross-linking, and the cross-linking agent is in excess; the molar ratio of the cross-linking unit is 75%; the salt form is hydrochloride.

[0092] At room temperature, dissolve polyallylamine hydrochloride (10 g, weight-average molecular weight 18,000) in water (100 mL), add S-methylisothiourea hemisulfate (3.72 g), add sodium bicarbonate (31.4 g), react at 50 °C for 16 hours, monitor by HPLC until S-methylisothiourea hemisulfate is completely consumed, and adjust the pH of the system to 7 using hydrochloric acid (6 N). While stirring, add methanol (100 mL) dropwise to the reaction solution to form a viscous solid. Pour out the supernatant, wash the solid with methanol, dry it under reduced pressure at 70 °C, and grind it with a pulverizer to obtain Example 4A (9.6 g), which is a white solid.

[0093] At room temperature, add Example 4A (1.0 g) to water (3 mL), and adjust the pH of the system to 11 using an aqueous sodium hydroxide solution (10 N). At room temperature, add Span 85 (41 mg) to toluene (8 mL), and stir to completely disperse and homogenize. At room temperature, add the toluene solution of Span 85 to the aqueous solution of Example 4A, maintain the stirring state, add epichlorohydrin (988 mg), and after addition, maintain stirring and react at room temperature for 16 hours. Filter the reaction solution, slurry the crude product with water and filter, repeat twice, then slurry the crude product with isopropanol and filter, repeat twice. After drying the wet filter cake under reduced pressure at 70 °C, grind it with a pulverizer to obtain Example 4 (1.44 g), which is a powdery white solid.

[0094] Example 5

[0095] The structure of Example 5 is as shown in General Formula I, characterized in that: the weight-average molecular weight of the raw material polyallylamine is 18,000; the guanidinylation reagent is S-methylisothiourea hemisulfate, and the molar ratio of the guanidine unit is 35%; the cross-linking method is epichlorohydrin cross-linking with an excess of cross-linking agent; the molar ratio of the cross-linking unit is 65%; the salt form is hydrochloride.

[0096] At room temperature, polyallylamine hydrochloride (10 g, weight-average molecular weight 18,000) was dissolved in water (100 mL), S-methylisothiourea hemisulfate (5.2 g) was added, sodium bicarbonate (31.4 g) was added, and the reaction was carried out at 50 °C for 40 hours. HPLC was used to monitor the complete consumption of S-methylisothiourea hemisulfate, and a viscous solid was formed. The supernatant was poured out, the solid was washed with water, dried under reduced pressure at 70 °C, and ground with a pulverizer to obtain Example 5A (13.64 g), which was a white solid.

[0097] At room temperature, Example 5A (3.0 g) was added to water (9 mL), and the pH of the system was adjusted to 11 using an aqueous sodium hydroxide solution (10 N). At room temperature, Span 85 (120 mg) was added to toluene (24 mL), and stirred until completely dispersed and uniform. At room temperature, the toluene solution of Span 85 was added to the aqueous solution of Example 5A, and stirring was maintained. Epichlorohydrin (2.48 g) was added, and after addition, the reaction was carried out at room temperature with stirring for 16 hours. The reaction solution was filtered, the crude product was slurried with water and filtered, and this was repeated twice. Then the crude product was slurried with isopropanol and filtered, and this was repeated twice. The wet filter cake was dried under reduced pressure at 70 °C and ground with a pulverizer to obtain Example 5 (2.1 g), which was a powdery white solid.

[0098] Example 6

[0099] The structure of Example 6 is as shown in General Formula I, characterized in that: the weight-average molecular weight of the raw material polyallylamine is 18,000; the guanidinylation reagent is S-methylisothiourea hemisulfate, and the molar ratio of the guanidine unit is 50%; the cross-linking method is epichlorohydrin cross-linking with an excess of cross-linking agent; the molar ratio of the cross-linking unit is 50%; the salt form is hydrochloride.

[0100] At room temperature, polyallylamine hydrochloride (10 g, weight-average molecular weight 18,000) was dissolved in water (100 mL), S-methylisothiourea hemisulfate (7.45 g) was added, and the pH of the system was adjusted to 11 using an aqueous sodium hydroxide solution (10 N). The reaction was carried out at 50 °C for 16 hours. HPLC was used to monitor the complete consumption of S-methylisothiourea hemisulfate, and a viscous product was precipitated. Methanol (100 mL) was added dropwise to the reaction solution under stirring, and a spongy solid was formed. The reaction solution was filtered, and the solid was washed twice with water. The solid was dried under reduced pressure at 70 °C and ground with a pulverizer to obtain Example 6A (8.42 g), which was a white solid.

[0101] At room temperature, add Example 6A (2.0 g) to water (6 mL), and adjust the pH of the system to 11 using an aqueous sodium hydroxide solution (10 N). At room temperature, add Span 85 (86 mg) to toluene (16 mL), and stir to disperse it completely and evenly. At room temperature, add the toluene solution of Span 85 to the aqueous solution of Example 6A, keep stirring, add epichlorohydrin (1.21 g), and after addition, keep stirring and react at room temperature for 16 hours. Filter the reaction solution, slurry the crude product with water and filter, repeat twice, then slurry the crude product with isopropanol and filter, repeat twice. After drying the wet filter cake under reduced pressure at 70 °C, grind it with a pulverizer to obtain Example 6 (2.82 g), which is a powdery white solid.

[0102] Example 7

[0103] The structure of Example 7 is shown in General Formula I, and its characteristics are as follows: the weight-average molecular weight of the raw material polyallylamine is 18,000; the guanidinylation reagent is S-methylisothiourea hemisulfate, and the molar ratio of the guanidine unit is 65%; the cross-linking method is epichlorohydrin cross-linking, and the cross-linking agent is in excess; the molar ratio of the cross-linking unit is 35%; the salt form is hydrochloride.

[0104] At room temperature, dissolve polyallylamine hydrochloride (10 g, weight-average molecular weight 18,000) in water (100 mL), add S-methylisothiourea hemisulfate (9.69 g), use an aqueous sodium hydroxide solution (10 N) to adjust the pH of the system to 11, react at 50 °C for 20 hours, monitor by HPLC until S-methylisothiourea hemisulfate is completely consumed, and a viscous product precipitates. Dropwise add methanol (100 mL) to the reaction solution under stirring to form a spongy solid. Filter the reaction solution, wash the solid twice with water, dry the solid under reduced pressure at 70 °C, and grind it with a pulverizer to obtain Example 7A (6.65 g), which is a white solid.

[0105] At room temperature, add Example 7A (2.0 g) to water (6 mL), and adjust the pH of the system to 11 using an aqueous sodium hydroxide solution (10 N). At room temperature, add Span 85 (86 mg) to toluene (16 mL), and stir to disperse it completely and evenly. At room temperature, add the toluene solution of Span 85 to the aqueous solution of Example 7A, keep stirring, add epichlorohydrin (811 mg), and after addition, keep stirring and react at room temperature for 16 hours. Filter the reaction solution, slurry the crude product with water and filter, repeat twice, then slurry the crude product with isopropanol and filter, repeat twice. After drying the wet filter cake under reduced pressure at 70 °C, grind it with a pulverizer to obtain Example 7 (2.41 g), which is a powdery white solid.

[0106] Example 8

[0107] The structure of Example 8 is shown in General Formula I, and its characteristics are as follows: the weight-average molecular weight of the raw material polyallylamine is 18,000; the guanidinylation reagent is 1H-pyrazole-1-carboxamidine hydrochloride, and the molar ratio of the guanidine unit is 5%; the crosslinking method is epichlorohydrin crosslinking; the molar ratio of the crosslinking unit is 18%; the salt form is hydrochloride.

[0108] At room temperature, polyallylamine hydrochloride (2.5 g, weight-average molecular weight 18,000) and 1H-pyrazolecarboxamidine hydrochloride (196 mg) were added to PBS buffer solution (pH 7.4, 75 mL), and the pH of the system was adjusted to 9.5 using aqueous sodium hydroxide solution (4N). The reaction was carried out at room temperature for 48 hours, and HPLC was used to monitor the complete consumption of 1H-pyrazolecarboxamidine hydrochloride. The reaction solution was transferred to an activated dialysis bag (cut-off molecular weight 14,000) and dialyzed for 72 hours. The reaction solution was freeze-dried to obtain Example 8A (2.76 g), which is a white solid.

[0109] At room temperature, Example 8A (2.76 g) was added to water (9 mL), and the pH of the system was adjusted to 10 using aqueous sodium hydroxide solution (10N). At room temperature, Span 85 (123 mg) was added to toluene (22 mL), and stirred until completely dispersed and uniform. At room temperature, the toluene solution of Span 85 was added to the aqueous solution of Example 8A, and stirring was maintained. Epichlorohydrin (238 mg) was added, and after addition, the reaction was carried out at room temperature with stirring for 16 hours. The reaction solution was filtered, and the crude product was slurried with water and filtered, and this was repeated twice. Then the crude product was slurried with isopropanol and filtered, and this was repeated twice. The wet filter cake was dried under reduced pressure at 70 °C and then ground by a pulverizer to obtain Example 8 (2.29 g), which is a powdery white solid.

[0110] Example 9

[0111] The structure of Example 9 is shown in General Formula I, and its characteristics are as follows: the weight-average molecular weight of the raw material polyallylamine is 18,000; the guanidinylation reagent is S-methylisothiourea hemisulfate, and the molar ratio of the guanidine unit is 15%; the crosslinking method is epichlorohydrin crosslinking; the molar ratio of the crosslinking unit is 16%; the salt form is hydrochloride.

[0112] At room temperature, polyallylamine hydrochloride (70 g, weight-average molecular weight 18,000) was dissolved in water (700 mL), S-methylisothiourea hemisulfate (15.62 g) was added, and sodium bicarbonate (166.6 g) was added. The reaction was carried out at 50 °C for 40 hours, and HPLC was used to monitor the complete consumption of S-methylisothiourea hemisulfate. The pH of the system was adjusted to 7 using hydrochloric acid (6N). Methanol (700 mL) was added dropwise to the reaction solution under stirring to form a translucent gel. The gel was centrifuged and collected, dried under reduced pressure at 70 °C, and then ground by a pulverizer to obtain Example 9A (44.2 g), which is a white solid.

[0113] At room temperature, add Example 9A (22.1 g) to water (66 mL), and adjust the pH of the system to 11 using an aqueous sodium hydroxide solution (10 N). At room temperature, add Span 85 (0.86 g) to toluene (177 mL), and stir to completely disperse and homogenize. At room temperature, add the toluene solution of Span 85 to the aqueous solution of Example 9A, keep stirring, add epichlorohydrin (1.66 g), and keep stirring at room temperature for 16 hours after addition. Filter the reaction solution, slurry the crude product with water and filter, repeat twice, then slurry the crude product with isopropanol and filter, repeat twice. After drying the wet filter cake under reduced pressure at 70 °C, grind it with a pulverizer to obtain Example 9 (19.2 g), which is a powdery white solid.

[0114] Elemental analysis:

[0115] Element Nitrogen Carbon Hydrogen Sulfur Oxygen Content (%) 17.62 39.36 8.55 1.92 12.59

[0116] Example 10

[0117] The structure of Example 10 is shown in General Formula I, and its characteristics are as follows: the weight-average molecular weight of the raw material polyallylamine is 18000; the guanidinylation reagent is 1H-pyrazole-1-carboximidamide hydrochloride, and the molar ratio of the guanidine unit is 30%; the cross-linking method is epichlorohydrin cross-linking; the molar ratio of the cross-linking unit is 18%; the salt form is hydrochloride.

[0118] At room temperature, add polyallylamine hydrochloride (2.5 g, weight-average molecular weight 18000) and pyrazolecarboximidamide hydrochloride (1.18 g) to PBS buffer solution (pH 7.4, 75 mL), adjust the pH of the system to 9.5 using an aqueous sodium hydroxide solution (4 N), react at room temperature for 48 hours, monitor by HPLC until pyrazolecarboximidamide hydrochloride is completely consumed, and transfer the reaction solution to an activated dialysis bag (cut-off molecular weight 14000) for dialysis for 72 hours. Lyophilize the reaction solution to obtain Example 10A (1.8 g), which is a white solid.

[0119] At room temperature, add Example 10A (1.8 g) to water (5.4 mL), and adjust the pH of the system to 10 using an aqueous sodium hydroxide solution (10 N). At room temperature, add Span 85 (73 mg) to toluene (14.4 mL), and stir to completely disperse and homogenize. At room temperature, add the toluene solution of Span 85 to the aqueous solution of Example 10A, keep stirring, add epichlorohydrin (141 mg), and keep stirring at room temperature for 16 hours after addition. Filter the reaction solution, slurry the crude product with water and filter, repeat twice, then slurry the crude product with isopropanol and filter, repeat twice. After drying the wet filter cake under reduced pressure at 70 °C, grind it with a pulverizer to obtain Example 10 (1.15 g), which is a powdery white solid.

[0120] Example 11

[0121] The structure of Example 11 is shown in General Formula I, and its characteristics are as follows: the weight-average molecular weight of the raw material polyallylamine is 18,000; the guanidinylation reagent is 1H-pyrazole-1-carboxamidine hydrochloride, and the molar ratio of the guanidine unit is 50%; the crosslinking method is epichlorohydrin crosslinking; the molar ratio of the crosslinking unit is 18%; the salt form is hydrochloride.

[0122] At room temperature, polyallylamine hydrochloride (2.5 g, weight-average molecular weight 18,000) and pyrazolecarboxamidine hydrochloride (1.97 g) were added to PBS buffer solution (pH 7.4, 75 mL). The pH of the system was adjusted to 9.5 using aqueous sodium hydroxide solution (4 N), and the reaction was carried out at room temperature for 48 hours. HPLC was used to monitor the complete consumption of pyrazolecarboxamidine hydrochloride. The reaction solution was transferred to an activated dialysis bag (cut-off molecular weight 14,000) and dialyzed for 72 hours. The reaction solution was freeze-dried to obtain Example 11A (1.88 g), which is a white solid.

[0123] At room temperature, Example 11A (1.88 g) was added to water (5.64 mL), and the pH of the system was adjusted to 10 using aqueous sodium hydroxide solution (10 N). At room temperature, Span 85 (71 mg) was added to toluene (15 mL), and stirred until completely dispersed and homogeneous. At room temperature, the toluene solution of Span 85 was added to the aqueous solution of Example 11A, and stirring was maintained. Epichlorohydrin (137 mg) was added, and after addition, the reaction was carried out at room temperature with stirring for 16 hours. The reaction solution was filtered, and the crude product was slurried with water and filtered, and this was repeated twice. Then the crude product was slurried with isopropanol and filtered, and this was repeated twice. The wet filter cake was dried under reduced pressure at 70 °C and then ground by a pulverizer to obtain Example 11 (1.02 g), which is a powdery white solid.

[0124] Example 12

[0125] The structure of Example 12 is shown in General Formula I, and its characteristics are as follows: the weight-average molecular weight of the raw material polyallylamine is 3,100; the guanidinylation reagent is 1H-pyrazole-1-carboxamidine hydrochloride, and the molar ratio of the guanidine unit is 15%; the crosslinking method is epichlorohydrin crosslinking; the molar ratio of the crosslinking unit is 28%; the salt form is hydrochloride.

[0126] At room temperature, polyallylamine hydrochloride (2.5 g, weight-average molecular weight 3,100) and 1H-pyrazole-1-carboxamidine hydrochloride (588 mg) were added to PBS buffer solution (pH 7.4, 75 mL). The pH of the system was adjusted to 9.5 using aqueous sodium hydroxide solution (4 N), and the reaction was carried out at room temperature for 48 hours. HPLC was used to monitor the complete consumption of pyrazolecarboxamidine hydrochloride. The reaction solution was transferred to an activated dialysis bag (cut-off molecular weight 1,500) and dialyzed for 72 hours. The reaction solution was freeze-dried to obtain Example 12A (0.58 g), which is a white solid.

[0127] At room temperature, add Example 12A (0.58 g) to water (4 mL), and adjust the pH of the system to 10 using an aqueous sodium hydroxide solution (10 N). At room temperature, add Span 85 (39 mg) to toluene (10.7 mL), and stir until completely dispersed and homogeneous. At room temperature, add the toluene solution of Span 85 to the aqueous solution of Example 12A, maintain the stirring state, add epichlorohydrin (76 mg), and after addition, maintain stirring and react at room temperature for 16 hours. Filter the reaction solution, slurry the crude product with water and filter, repeat twice, then slurry the crude product with isopropanol and filter, repeat twice. After drying the wet filter cake under reduced pressure at 70 °C, grind it with a pulverizer to obtain Example 12 (0.2 g), which is a powdery white solid.

[0128] Example 13

[0129] The structure of Example 13 is shown in General Formula I, and its characteristics are as follows: the weight-average molecular weight of the raw material polyallylamine is 3100; the guanidinylation reagent is 1H-pyrazole-1-carboxamidine hydrochloride, and the molar ratio of the guanidine unit is 30%; the cross-linking method is cross-linking with epichlorohydrin; the molar ratio of the cross-linking unit is 28%; the salt form is hydrochloride.

[0130] At room temperature, add polyallylamine hydrochloride (2.5 g, weight-average molecular weight 3100) and pyrazolecarboxamidine hydrochloride (1180 g) to PBS buffer solution (pH 7.4, 75 mL), adjust the pH of the system to 9.5 using an aqueous sodium hydroxide solution (4 N), react at room temperature for 48 hours, monitor by HPLC until pyrazolecarboxamidine hydrochloride is completely consumed, and transfer the reaction solution to an activated dialysis bag (cut-off molecular weight 1500) for dialysis for 72 hours. Lyophilize the reaction solution to obtain Example 13A (1.73 g), which is a white solid.

[0131] At room temperature, add Example 13A (1.73 g) to water (22 mL), and adjust the pH of the system to 10 using an aqueous sodium hydroxide solution (10 N). At room temperature, add Span 85 (110 mg) to toluene (58 mL), and stir until completely dispersed and homogeneous. At room temperature, add the toluene solution of Span 85 to the aqueous solution of Example 13A, maintain the stirring state, add epichlorohydrin (210 mg), and after addition, maintain stirring and react at room temperature for 16 hours. Filter the reaction solution, slurry the crude product with water and filter, repeat twice, then slurry the crude product with isopropanol and filter, repeat twice. After drying the wet filter cake under reduced pressure at 70 °C, grind it with a pulverizer to obtain Example 13 (0.61 g), which is a powdery white solid.

[0132] Example 14

[0133] The structure of Example 14 is shown in General Formula I, and its characteristics are as follows: the weight-average molecular weight of the raw material polyallylamine is 3100; the guanidinylation reagent is 1H-pyrazole-1-carboximidamide hydrochloride, and the molar ratio of the guanidine unit is 50%; the cross-linking method is epichlorohydrin cross-linking; the molar ratio of the cross-linking unit is 27%; the salt form is hydrochloride.

[0134] At room temperature, polyallylamine hydrochloride (2.5 g, weight-average molecular weight 3100) and 1H-pyrazole-1-carboximidamide hydrochloride (1970 mg) were added to PBS buffer solution (pH 7.4, 75 mL). The pH of the system was adjusted to 9.5 using aqueous sodium hydroxide solution (4 N), and the reaction was carried out at room temperature for 48 hours. HPLC was used to monitor the complete consumption of pyrazolecarboximidamide hydrochloride. The reaction solution was transferred to an activated dialysis bag (cut-off molecular weight 1500) and dialyzed for 72 hours. The reaction solution was freeze-dried to obtain Example 14A (0.93 g), which was a white solid.

[0135] At room temperature, Example 14A (0.93 g) was added to water (5 mL), and the pH of the system was adjusted to 10 using aqueous sodium hydroxide solution (10 N). At room temperature, span 85 (50 mg) was added to toluene (13.5 mL), and stirred until completely dispersed and uniform. At room temperature, the toluene solution of span 85 was added to the aqueous solution of Example 14A, and stirring was maintained. Epichlorohydrin (100 mg) was added, and after addition, the reaction was carried out at room temperature with stirring for 16 hours. The reaction solution was filtered, and the crude product was slurried with water and filtered, and this was repeated twice. Then the crude product was slurried with isopropanol and filtered, and this was repeated twice. The wet filter cake was dried under reduced pressure at 70 °C, ground by a pulverizer, and Example 14 (0.35 g) was obtained, which was a powdery white solid.

[0136] Example 15

[0137] The structure of Example 15 is shown in General Formula I, and its characteristics are as follows: the weight-average molecular weight of the raw material polyallylamine is 17000; the guanidinylation reagent is 1H-pyrazole-1-carboximidamide hydrochloride, and the molar ratio of the guanidine unit is 15%; the cross-linking method is epichlorohydrin cross-linking; the molar ratio of the cross-linking unit is 6%; the salt form is hydrochloride.

[0138] At room temperature, polyallylamine hydrochloride (105.44 g, weight-average molecular weight 18000) and 1H-pyrazole-1-carboximidamide hydrochloride (24.78 g) were added to PBS buffer solution (pH 7.4, 3320 mL). The pH of the system was adjusted to 9.5 using aqueous sodium hydroxide solution (4 N), and the reaction was carried out at room temperature for 48 hours. HPLC was used to monitor the complete consumption of pyrazolecarboximidamide hydrochloride. The reaction solution was transferred to an activated dialysis bag (cut-off molecular weight 14000) and dialyzed for 72 hours. The reaction solution was freeze-dried to obtain Example 15A (73.5 g), which was a white solid.

[0139] At room temperature, add Example 15A (0.7 g) to water (2.1 mL), and adjust the pH of the system to 10 using an aqueous sodium hydroxide solution (10 N). At room temperature, add Span 85 (30 mg) to toluene (6 mL), and stir to completely disperse and homogenize. At room temperature, add the toluene solution of Span 85 to the aqueous solution of Example 15A, maintain the stirring state, add epichlorohydrin (19 mg), and after addition, maintain stirring and react at room temperature for 16 hours. Filter the reaction solution, slurry the crude product with water and filter, repeat twice, then slurry the crude product with isopropanol and filter, repeat twice. After drying the wet filter cake under reduced pressure at 70 °C, grind it with a pulverizer to obtain Example 15 (0.31 g), which is a white solid in powder form.

[0140] Example 16

[0141] The structure of Example 16 is shown in General Formula I, and its characteristics are as follows: the weight-average molecular weight of the raw material polyallylamine is 17,000; the guanidinylation reagent is 1H-pyrazole-1-carboxamidine hydrochloride, and the molar ratio of the guanidine unit is 15%; the crosslinking method is crosslinking with epichlorohydrin; the molar ratio of the crosslinking unit is 12%; the salt form is hydrochloride.

[0142] At room temperature, add Example 15A (0.7 g) to water (2.1 mL), and adjust the pH of the system to 10 using an aqueous sodium hydroxide solution (10 N). At room temperature, add Span 85 (30 mg) to toluene (6 mL), and stir to completely disperse and homogenize. At room temperature, add the toluene solution of Span 85 to the aqueous solution of Example 15A, maintain the stirring state, add epichlorohydrin (39 mg), and after addition, maintain stirring and react at room temperature for 16 hours. Filter the reaction solution, slurry the crude product with water and filter, repeat twice, then slurry the crude product with isopropanol and filter, repeat twice. After drying the wet filter cake under reduced pressure at 70 °C, grind it with a pulverizer to obtain Example 16 (0.42 g), which is a white solid in powder form.

[0143] Example 17

[0144] The structure of Example 17 is shown in General Formula I, and its characteristics are as follows: the weight-average molecular weight of the raw material polyallylamine is 17,000; the guanidinylation reagent is 1H-pyrazole-1-carboxamidine hydrochloride, and the molar ratio of the guanidine unit is 15%; the crosslinking method is crosslinking with epichlorohydrin; the molar ratio of the crosslinking unit is 24%; the salt form is hydrochloride.

[0145] At room temperature, add Example 15A (0.7 g) to water (2.1 mL), and adjust the pH of the system to 10 using an aqueous sodium hydroxide solution (10 N). At room temperature, add Span 85 (30 mg) to toluene (6 mL), and stir to disperse it completely and evenly. At room temperature, add the toluene solution of Span 85 to the aqueous solution of Example 15A, keep stirring, add epichlorohydrin (78 mg), and after addition, keep stirring and react at room temperature for 16 hours. Filter the reaction solution, slurry the crude product with water and filter, repeat twice, then slurry the crude product with isopropanol and filter, repeat twice. After drying the wet filter cake under reduced pressure at 70 °C, grind it with a pulverizer to obtain Example 17 (0.52 g), which is a powdery white solid.

[0146] Example 18

[0147] The structure of Example 18 is shown in General Formula I, and its characteristics are as follows: the weight-average molecular weight of the raw material polyallylamine is 17,000; the guanidinylation reagent is 1H-pyrazole-1-carboxamidine hydrochloride, and the molar ratio of the guanidine unit is 15%; the crosslinking method is epichlorohydrin crosslinking; the molar ratio of the crosslinking unit is 30%; the salt form is hydrochloride.

[0148] At room temperature, add Example 15A (0.7 g) to water (2.1 mL), and adjust the pH of the system to 10 using an aqueous sodium hydroxide solution (10 N). At room temperature, add Span 85 (30 mg) to toluene (6 mL), and stir to disperse it completely and evenly. At room temperature, add the toluene solution of Span 85 to the aqueous solution of Example 15A, keep stirring, add epichlorohydrin (97 mg), and after addition, keep stirring and react at room temperature for 16 hours. Filter the reaction solution, slurry the crude product with water and filter, repeat twice, then slurry the crude product with isopropanol and filter, repeat twice. After drying the wet filter cake under reduced pressure at 70 °C, grind it with a pulverizer to obtain Example 18 (0.3 g), which is a powdery white solid.

[0149] Example 19

[0150] The structure of Example 19 is shown in General Formula I, and its characteristics are as follows: the weight-average molecular weight of the raw material polyallylamine is 18,000; the guanidinylation reagent is S-methylisothiourea hemisulfate, and the molar ratio of the guanidine unit is 15%; the crosslinking method is epichlorohydrin crosslinking; the molar ratio of the crosslinking unit is 16%; the salt form is carbonate.

[0151] At room temperature, add Example 9 (3 g), sodium carbonate (9.56 g), and water (70 mL) to a three-necked flask, react overnight at room temperature, filter the reaction solution, slurry the crude product with water and filter, and after drying the wet filter cake under reduced pressure at 70 °C, grind it with a pulverizer to obtain a powdery white solid, which is Example 19 (2.2 g).

[0152] Experiment on the in vitro phosphate-binding ability of guanidine group-containing crosslinked polymers

[0153] Dissolve N,N-2-(2-hydroxyethyl)-2-aminoethanesulfonic acid (21.33 g), sodium chloride (4.64 g) and potassium dihydrogen phosphate (2.72 g) in water, make up the volume to 1000 mL, divide the solution into two parts, and adjust the pH to 4 and 7 respectively with 10N sodium hydroxide solution to obtain phosphate solutions with pH 4 and 7.

[0154] Add the polymer to be tested (40 mg) to the phosphate solutions with pH 4 and 7 (20 mL) respectively. After shaking on a shaker at 37 °C for 16 hours, centrifuge and collect the supernatant. Detect the phosphate residue in the supernatant by the following method.

[0155] Table 1. Test method for the in vitro phosphorus-binding ability of guanidine group-containing crosslinked polymers

[0156]

[0157]

[0158] After color development with the kit, use an ultraviolet spectrophotometer to measure the phosphate level in the supernatant. By comparing the phosphate residues in the supernatant and the test solution, calculate the difference, which is the phosphate bound by 40 mg of the polymer, and is expressed in the unit of (PO4 3- ) mg / (polymer) g. The results are summarized in Table 2 below.

[0159] Table 2. Phosphate-binding ability of crosslinked polymers to phosphate solutions

[0160]

[0161]

[0162] Example 21 In vivo pharmacodynamic experiment of guanidine group-containing crosslinked polymers

[0163] Evaluate the effect of guanidine group-containing crosslinked polymers on urinary phosphorus in healthy male Sprague Dawley rats after a high-phosphorus diet, and compare the pharmacodynamic effects with the positive phosphorus-lowering drug sevelamer.

[0164] Preparation of feed

[0165] Normal feed: Use 990 g of powdered feed as raw material, add an appropriate amount of water and manually form it into short rod-shaped feed with a length of 5-10 cm and a diameter of about 1 cm. After convective drying at 100 °C for 2 hours, then vacuum drying at 60 °C for 16 hours, and store it at room temperature in a cool and dry place for later use after taking it out of the oven.

[0166] Blank high-phosphorus feed: 6.46 g of KH2PO4 and 3.34 g of K2HPO4 were uniformly mixed into 990 g of powder feed, an appropriate amount of water was added and manually formed into a shape with a length of 5 - 10 cm. After convective drying at 100 °C for 2 hours, it was then vacuum dried at 60 °C for 16 hours. After taking it out of the oven, it was stored at room temperature in a cool and dry place for later use.

[0167] Drug-containing high-phosphorus feed: 10.0 g of the test substance, together with 6.46 g of KH2PO4 and 3.34 g of K2HPO4, were uniformly mixed into 980 g of powder feed, an appropriate amount of water was added and manually formed into a short rod-shaped feed with a length of 5 - 10 cm and a diameter of about 1 cm. After convective drying at 100 °C for 2 hours, it was then vacuum dried at 60 °C for 16 hours. After taking it out of the oven, it was stored at room temperature in a cool and dry place for later use. (The content of the test substance is about 1% of the total weight of the feed)

[0168] Experimental procedure

[0169] During the feeding stage, the experimental animals could eat freely and fasted when in the metabolic cage. The experimental animals could drink water freely. All urine phosphorus detections were carried out based on the detection method in Example 20.

[0170] After adapting the rats with ordinary feed for 3 days, the feed was replaced with blank high-phosphorus feed. After continuing to feed for 5 days, urine for 17 h during the period from 17:00 to 10:00 the next day was collected, the phosphorus concentration in the urine of the collected rats was detected, and the total amount of phosphorus in the 17-hour urine of the rats was calculated based on the urine volume (taking the average value). This was used as the urine phosphorus baseline level of the rats under a high-phosphorus diet.

[0171] The rats with successful modeling were randomly divided into 3 groups, with 3 rats in each group. The first group continued to be fed with blank high-phosphorus feed, the second group was fed with high-phosphorus feed containing the positive control drug sevelamer in Example 1, and the third group was fed with drug-containing high-phosphorus feed containing the product in Example 9. After feeding for 3 days, urine for 17 h during the period from 17:00 to 10:00 the next day was collected, the phosphorus concentration in the urine of the collected rats was detected, and the total amount of phosphorus in the 17-hour urine of the rats was calculated. The results are shown in Figure 1 In.

[0172] From the above results, it can be seen that the phosphate binder according to the present invention can effectively bind phosphate both in vitro and in vivo. Although the phosphate-binding ability of the phosphate binder according to the present invention to phosphate in vitro is weaker than that of sevelamer, its effect of reducing urine phosphorus in rats is unexpectedly better than that of sevelamer. Therefore, the guanidine group-containing crosslinked polymer can significantly reduce the urine phosphorus level in rats in vivo. That is to say, compared with sevelamer, the guanidine group-containing crosslinked polymer can better bind phosphorus in the digestive tract, thereby reducing the absorption of phosphoric acid from the digestive tract into the blood circulation, and ultimately achieving the reduction of the level of phosphoric acid in the blood.

[0173] Although the present invention has been described with reference to numerous embodiments and examples, those of ordinary skill in the art will recognize, based on the disclosure of the present invention, that other embodiments can be designed without departing from the scope and spirit of the present invention.

Claims

1. A phosphate binder that comprises at least one guanidine group-containing crosslinked polymer or a pharmaceutically acceptable salt thereof, wherein, The guanidine group-containing crosslinked polymer is derived from polyallylamine or a pharmaceutically acceptable salt thereof, wherein the guanidine group-containing crosslinked polymer comprises a guanidine group structural unit and a crosslinked structural unit, and wherein the guanidine group structural unit and the crosslinked structural unit are represented by the following formulas (1) and (2), respectively:

2. The phosphate binder according to claim 1, wherein, The guanidine group-containing crosslinked polymer further comprises an amino group structural unit, and the amino group structural unit is represented by the following formula (3):

3. The phosphate binder according to claim 1 or 2, wherein, Based on the total molar amount of the amino group structural unit, the guanidine group structural unit, and the crosslinked structural unit, the molar content of the guanidine group structural unit ranges from 5 mol% to 65 mol%, preferably from 10 mol% to 25 mol%; the molar content of the crosslinked structural unit ranges from 6 mol% to 95 mol%, preferably from 10 mol% to 20 mol%; and the molar content of the amino group structural unit ranges from 0 to 77 mol%, preferably from 50 mol% to 70 mol%.

4. The phosphate binder according to claim 1 or 2, wherein The polyallylamine has a weight average molecular weight of 3000 to 18000, and the weight average molecular weight is determined by GPC.

5. The phosphate binder according to claim 1 or 2, wherein, The guanidine group structural unit is derived from a guanidinylation reagent selected from S-methylisothiourea hemisulfate and 1H-pyrazole-1-carboxamidine hydrochloride.

6. The phosphate binder according to claim 1 or 2, wherein The pharmaceutically acceptable salt includes hydrochloride or carbonate.

7. The phosphate binder according to claim 1 or 2, wherein The phosphate binder is a powdery solid.

8. The method for preparing a phosphate binder according to any one of claims 1 to 7, the method comprising the following steps: a) providing the polyallylamine or a pharmaceutically acceptable salt thereof as a polymer substrate; b) reacting the substrate with the guanidinylation reagent to form a guanidinylated polymer substrate; c) subjecting the guanidinylated substrate to a ring-opening reaction with epichlorohydrin to form a guanidine group-containing crosslinked polymer substrate; and d) optionally, subjecting the guanidine group-containing crosslinked polymer substrate to an acid addition reaction.

9. A pharmaceutical composition comprising the phosphate binder according to any one of claims 1 to 7, and one or more pharmaceutically acceptable carriers, adjuvants or excipients.

10. Use of the phosphate binder according to any one of claims 1 to 7 or the pharmaceutical composition according to claim 9 in the manufacture of a medicament for treating hyperphosphatemia in a subject in need thereof.

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