Pharmaceutical compositions containing at least one protein-based active ingredient that is protected against digestive enzymes.

Description

[0001] The main object of the present invention is compositions, compositions for use as medicinal products, or pharmaceutical compositions, containing at least one protein active ingredient protected from digestive enzymes. Within said compositions, said at least one active ingredient is formulated so as to resist, in its current state, its metabolism in the gastric and intestinal environments. These compositions are for oral administration. (via the gastrointestinal tract) of said at least one protein active principle (sensitive to digestive enzymes).

[0002] To date, protein-based active ingredients, which are sensitive to digestive enzymes, particularly insulin and its analogues (more precisely sensitive to proteases, such as pepsin in the stomach and mainly trypsin in the intestine), are still mainly administered parenterally despite the numerous studies that have been carried out to propose alternative delivery routes (particularly more comfortable for patients).

[0003] The article by Simona Cernea and Itamar Raz, published in Timely Top. Med. Cardiovasc. Dis. 2006 Nov. 1; Vol 10: E29, provided an overview in 2006 of alternative forms of insulin administration to injection. Numerous patent documents, such as WO 85 / 05029, US 5,824,638, and WO 2006 / 127361, also exist on this subject.

[0004] The most advanced research concerns nasal administration. This route of administration is indeed less technically demanding than parenteral administration. The richly vascularized nasal mucosa has the capacity to absorb proteins and transmit them to the bloodstream, making it a potentially interesting candidate. However, it presents some difficulty in controlling the dose delivered by inhalers according to the patient (particularly in the case of a cold).

[0005] According to prior art, chemically modified protein active ingredients and formulated protein active ingredients were more commonly described in numerous variations. For example: US patent 4,692,433 (D9) describes the oral administration of polypeptide hormones. These hormones are administered, advantageously, in buffered aqueous solutions encapsulated in a liposome. They are not administered in free form. Documents WO 97 / 33531 (D3), WO 02 / 072075 (D5), and US 2003 / 0017203 (D4) describe gastro-resistant formulations for the oral administration of peptides. These formulations combine a gastro-resistant coating and a pH-reducing agent. This coating protects the active ingredient during its passage through the stomach. Once in the intestinal compartment, the coating dissolves, releasing both the active ingredient and the pH-reducing agent. Due to the action of said pH-reducing agent, the pH of the intestine is locally lowered, thereby reducing the proteolytic activity of the intestinal proteases present.Protection at the level of the stomach and at the entrance to the intestine is therefore ensured by two different mechanisms, which exert their effects sequentially. The peptides involved do not act in their free form, nor in the presence of a buffer. It is worth noting here that Table 1, presented on page 23 of application WO 97 / 33531, shows bioavailability results for buffered calcitonin solutions. The tests were carried out to study the influence of the pH of the solution administered locally (directly into the intestine of rats) on the absorption of the active ingredient. These tests were conducted with a view to optimizing the nature of the pH-reducing agent used in the proposed gastro-resistant formulation.These tests do not describe, nor do they suggest, the oral compositions (pharmaceutical compositions or drugs) of the invention described below; US application 2002 / 0132757 (D1) relates to the administration of calcitonin, in the form of solid particles, through epithelial membranes, via the oral or nasal mucosa. For this specific type of administration, which does not involve the gastrointestinal tract, the active ingredient is processed as follows. It is first dissolved in a buffer (a simple manufacturing aid). The resulting solution, with the addition of surfactant(s) and absorption-enhancing agent(s), is lyophilized. The resulting dry particles are then packaged in a pressurized container with a suitable solvent or vehicle (ethanol, for example). This solvent or vehicle serves to disperse the particles under pressure over the largest possible surface area of ​​the mucosa.These particles are not administered in the presence of a buffer; US patent application 2007 / 0154559 (D2) describes a complex process for formulating active pharmaceutical ingredients (APIs) for oral administration. Enhanced gastrointestinal absorption is desired. The absorption in question is that of nanoparticles containing the APIs. According to the described process, the API is first dissolved in a buffer (a simple processing aid) and then complexed with a counterion. The resulting complex is dissolved, in the presence of a polymer and a lipid, in an organic solvent. An emulsion is then generated between the resulting organic solution and an aqueous solution containing an emulsifying agent. The nanoparticles are finally formed by evaporation of the organic solvent.The active ingredient is thus administered neither in free form nor in the presence of a buffer; application WO 2007 / 032018 (D8) describes a complex process for formulating active ingredients for oral administration, of the same type as that described in the US application above. The active ingredient is also delivered in the form of nanoparticles. These nanoparticles (based on a fatty acid and a polymer) are pH-sensitive. They shrink at acidic pH. The active ingredient is thus better protected during its passage through the stomach. Here again, the active ingredient is administered neither in free form nor in the presence of a buffer; application FR 2 123 524 (D6) describes an insulin derivative obtained by acylation. The chemical reaction in question is carried out in a buffered medium. Application WO 01 / 36656 (D7) describes a biomolecule / hyaluronic acid complex.These two prior art documents neither describe nor suggest pharmaceutical compositions combining their active ingredient in free form with a protective buffer system.

[0006] The teaching of the prior art documents mentioned above has been reported, with reference to the notions of oral composition, free form of the protein active ingredient and buffer, insofar as the said notions constitute the basis of the present invention, described below.

[0007] The technical problem of orally administering a protein-based active ingredient (therefore sensitive to digestive enzymes) is twofold, since the proposed protection system must a priori It must be effective both in the stomach and at the entrance to the intestine. a prioriFirst, the stomach resists gastric juice, and then pancreatic juice. Indeed, at the pylorus, as the acidic chyme empties into the duodenum, secretin is released from the intestine and stimulates the pancreas to secrete bicarbonate (to reduce the acidity of the chyme) and cholecystokinin, a pancreoenzyme that stimulates the secretion of pancreatic juice rich in enzymes (trypsinogen, chymotrypsinogen, which are converted into trypsin and chymotrypsin activated by enterokinase). Once the acidity is neutralized in the duodenum by secretin, negative feedback occurs, inhibiting pancreatic secretions. This normal digestive mechanism is familiar to those skilled in the art.

[0008] Faced with the technical problem of orally administering a protein-based active ingredient, the inventors propose a completely original solution, not based on a dual protection system, but on a protective system at the stomach level that also inhibits pancreatic secretion (thus eliminating the problem of the active ingredient's degradation at the entrance to the intestine). The inventors propose in retrospect This explains the good results obtained with the compositions of the invention. The original protection system proposed is a buffer system. Quite surprisingly, this original protection system, a buffer system, allows for oral administration. (via the gastrointestinal tract), of the protein active ingredient, in free form.

[0009] The present invention therefore relates to new compositions for use as a medicinal product or pharmaceutical compositions, intended for (suitable for) the oral administration of at least one protein active ingredient, buffered.

[0010] More specifically, the compositions of the invention are in liquid or solid form. They are oral compositions and contain at least one protein active ingredient. They are suitable for oral administration of said active ingredient.

[0011] Typically, these compositions: liquids contain a system (buffer system) capable of buffering them at a pH greater than 4 and less than or equal to 8; solids contain a system (buffer system) capable of exerting, when placed in a liquid medium, generally aqueous, a buffering effect between a pH greater than 4 and a pH less than or equal to 8.

[0012] According to its first objective, the present invention therefore relates to: compositions, in liquid or solid form, which contain: at least one protein active ingredient in free form, and, in liquids, a system (buffer system) capable of buffering them at a pH greater than 4 and less than or equal to 8, or, in solids, a system (buffer system) capable of exerting, when placed in a liquid medium, a buffering effect between a pH greater than 4 and a pH less than or equal to 8, for use as medicinal products, for oral administration ( via the gastrointestinal tract) of said at least one protein active ingredient, said at least one protein active ingredient being selected from (i) insulin, its analogues and derivatives, (ii) somatotropin, (iii) calcitonin, and (iv) LHRH analogues; pharmaceutical compositions, in liquid or solid form, for oral administration (viathe gastrointestinal tract), containing at least one protein active ingredient, which contain said protein active ingredient in free form, and, in liquids, a system (buffer system) capable of buffering them at a pH greater than 4 and less than or equal to 8, or, in solids, a system (buffer system) capable of exerting, when placed in a liquid medium, a buffering effect between a pH greater than 4 and a pH less than or equal to 8, said at least one protein active ingredient being selected from (i) insulin, its analogues and derivatives, (ii) somatotropin, (iii) calcitonin, and (iv) LHRH analogues.

[0013] The compositions of the invention are capable of being obtained by (simple) formulation, of said at least one protein active principle in free form, with a system (buffer system) capable of buffering them, in liquid form, at a pH greater than 4 and less than or equal to 8 or, in solid form, with a system (buffer system) capable of exerting, when their being placed in liquid medium of said solid form, a buffering effect between a pH greater than 4 and a pH less than or equal to 8.

[0014] Typically, the compositions of the invention, whether liquid or solid (monophasic, in any case), are oral compositions which combine within them said at least one protein active ingredient. in free form And a buffer system This buffer system, as described above, allows for the oral administration of the protein active ingredient in its free form. It is effective in protecting this free form during passage through the gastrointestinal tract.

[0015] Within the compositions of the invention, the active protein principle is therefore present, "as is", unprotected per se, particularly by a physical barrier... It is present as is or in simple mixture with excipients necessary for its formulation. By free form of said active ingredient, we mean in particular said active ingredient without a more or less complex physical protection system, such as coating, coating, matrix, capsule wall (said active ingredient is neither coated, nor coated, nor matrixed, nor encapsulated (particularly in liposomes)...).

[0016] The buffer system, given the stated pH values, is capable of buffering the compositions of the invention in a gastric environment. Andin the intestinal environment. It is obviously capable of exerting its buffering effect for the duration of digestion: for at least 2 hours, advantageously up to 3 hours (under the acidic conditions of the stomach and the alkaline conditions of the intestine). Those skilled in the art are familiar with such buffer systems. Their nature is described below, without being exhaustive.

[0017] The compositions of the invention combine: at least one free-form protein active ingredient (see above), generally A such an active principle (but the combined intervention of several active principles of this type (or even of at least one active principle of this type and at least one other active principle), in mixture or separately, is not excluded from the scope of the invention); and a system (buffer system) capable of exerting a buffering effect in the pH range stated above.

[0018] The exercise of said buffering effect in said pH zone (4 < pH ≤ 8) is obviously compatible with the stability of said at least one protein active principle (in any case with the stability of the active principle(s) present).

[0019] The compositions of the invention are buffered at a pH of 4 < pH ≤ 8. They are advantageously buffered at a pH between 4.5 and 7.5 (4.5 ≤ pH ≤ 7.5), most advantageously buffered at a pH between 5 and 7 (5 ≤ pH ≤ 7), or even at a pH greater than 5 and less than or equal to 7 (5 < pH ≤ 7). Most preferably, they are buffered at a pH of 6.5 or close to 6.5 (6.5 ± 0.2). This value is particularly preferred in the context where the composition of the invention contains insulin.

[0020] The compositions of the invention contain at least one protein active ingredient selected from (i) insulin, its analogs and derivatives, (ii) somatotropin, (iii) calcitonin, and (iv) LHRH analogs, which they are capable of protecting from digestive enzymes. Insulin has just been mentioned as such an active ingredient sensitive to digestive enzymes. The invention was developed particularly with reference to this active ingredient (see the examples and tests presented later in this text). The mechanism a priori in play (that the inventors propose) in retrospect ) - protection during passage through the stomach (at a pH > 4, pepsin is no longer (or hardly) active) and inhibition (more or less significant) of pancreatic secretions insofar as it is no longer acidic chyme that is poured into the duodenum - suitable for protecting the said protein active principles from digestive enzymes.

[0021] Thus, the compositions of the invention advantageously contain at least one protein active ingredient (in free form) selected from insulin, its analogues, and derivatives (they generally advantageously contain insulin or one of its analogues or derivatives as the sole active ingredient of this type, or even as the sole active ingredient). Those skilled in the art are familiar with insulin analogues such as, for example, insulin Lipro, insulin Aspart, insulin Glargine, and insulin Detemir. They are also familiar with insulin derivatives, such as those described in French patent application FR 2 123 524.

[0022] Thus, the compositions of the invention contain, as an active ingredient (in free form): insulin, one of its analogues or derivatives, somatotropin (human growth hormone), calcitonin, or an analogue of LHRH ("Luteinising Hormone Releasing Hormone"), such as tryptorelin. According to the present description, the compositions contain, as an active ingredient (in free form), somatotropin (human growth hormone) or one of its derivatives.

[0023] The buffer systems suitable for the purposes of the invention are conventional buffer systems, advantageously of high capacity. Those skilled in the art are familiar with such systems and are able to optimize a combination as defined by the invention: at least one protein active ingredient (in free form) / buffer system (for example: insulin / buffer system).

[0024] Without limiting the foregoing, it can be stated that the system responsible for the buffering effect within the compositions of the invention is advantageously a buffer selected from among the following buffers: phosphate, acetate, maleate, phthalate, succinate, citrate, imidazole, tetrabutylammonium, 2-amino-2-hydroxymethyl-1,3-propanediol (or trihydroxymethylaminomethane or Trometamol or Tham or Tris), tris-glycine, barbitol, tris-EDTA BSA, copper sulfate and zwitterionic acid.

[0025] More generally, the buffer system of the compositions of the invention can be chosen from the list of buffer systems given in the European Pharmacopoeia, current edition (monograph 4.1.3).

[0026] The said buffer system is advantageously a phosphate buffer or Tris.

[0027] As a phosphate buffer, a phosphate buffer containing the following is recommended: of 2 to 3% by mass of dihydrogenated monosodium phosphate, and of 97 to 98% by mass of monohydrogenated disodium phosphate which advantageously contains: about 2.8% by mass of dihydrogenated monosodium phosphate, and about 97.2% by mass of monohydrogenated disodium phosphate.

[0028] The oral compositions of the invention (combining in an original way at least one protein active ingredient, in free form, and the selected buffer system: 4 < pH ≤ 8) can exist according to two variants.

[0029] According to a first, more conventional variant, they are formulated as a unit. All the constituent ingredients, including the buffer system, are formulated together. Within this first variant, numerous possibilities exist. The compositions of the invention can, in particular, be in liquid forms (directly buffered to a suitable pH) such as solutions, suspensions, and syrups, or in solid forms (which develop a buffering effect upon ingestion in a liquid, generally water, or after ingestion in the stomach) such as tablets (conventional (to be swallowed), lozenges, sublingual, dispersible, orodispersible, effervescent), capsules, powders, effervescent powders, granules, effervescent granules, and lyophilized products. These lists are not exhaustive.The galenist knows how to formulate, in one or the other of the unitary forms listed above, the active principle in question with an appropriate system, responsible for the desired buffering effect.

[0030] In the preparation of effervescent dosage forms, it is necessary to add ingredients capable of imparting the desired effervescence. This type of ingredient (reagents, generally two reagents, capable of reacting and releasing gas) is familiar to those skilled in the art.

[0031] In this first variant, the compositions of the invention are advantageously presented in the form of solid galenic preparations, in particular dispersible tablets or effervescent tablets.

[0032] According to a second variant, the compositions of the invention are compositions with at least two separate components, in particular compositions which separately comprise: a component containing at least one protein active ingredient in free form; and another component containing at least the system generating the desired buffering effect.

[0033] These two components, separate, are to be administered jointly or almost jointly, so that, obviously, the buffering effect develops during the passage of the active ingredient through the digestive tract (first the stomach).

[0034] The compositions of the invention (according to the first or second of the above variants) which contain said at least one protein active ingredient in free form (or said at least one protein active ingredient in free form and at least one other active ingredient) and the associated buffer system, generally in a pharmaceutically acceptable excipient (with, if necessary, the ingredients suitable for making them effervescent), are obviously likely to contain other ingredients, used in a conventional way in galenics, such as sweetener, flavoring and / or manufacturing aids (lubricant, etc.)... The liquid compositions may contain only said at least one protein active ingredient (or said at least one protein active ingredient in free form and at least one other active ingredient) and the appropriate buffer system.In addition to these two components, they generally contain formulation ingredients commonly used in pharmaceutical formulation (such as the ingredients listed above). Solid compositions generally contain, in addition to at least one protein active ingredient (or even at least one protein active ingredient in free form and at least one other active ingredient) and a buffer system, a solid excipient (base, possibly with effervescent ingredients) with various additives (such as the ingredients listed above).

[0035] The preparation of the compositions of the invention, whether unitary or not, as described above, is also described in this description. Said preparation is a buffered or buffered dosage form. Characteristically, it comprises the (simple) formulation of at least one protein active ingredient in free form, with a buffer system capable of buffering said composition in liquid form (particularly in gastric and intestinal environments) at a pH greater than 4 and less than or equal to 8, or in solid form, with a buffer system capable of exerting, upon administration of said solid form into a liquid, particularly aqueous, medium (particularly in gastric and intestinal environments), a buffering effect between a pH greater than 4 and a pH less than or equal to 8.The term formulation is to be taken in the classical sense of the term (in galenics) for the preparation of unit compositions, in the broader sense (formulation = packaging) for the preparation of compositions with separate components.

[0036] In a conventional manner, other ingredients may be involved in the preparation of the compositions of the invention.

[0037] Those skilled in the art will have grasped the full potential of the present invention, as confirmed by the examples and test results presented below. The buffer's "dual positive effect"—gastro-protection and inhibition of pancreatic secretions—is particularly effective. This dual effect and its efficacy are truly remarkable.

[0038] In another aspect, the invention offers an original application for buffer systems and therefore also relates to the use of a buffer system as specified above, in particular chosen from those identified above, for the protection of at least one free-form protein active ingredient during its transit via the gastrointestinal tract, said at least one protein active ingredient being selected from (i) insulin, its analogs and derivatives, (ii) somatotropin, (iii) calcitonin, and (iv) LHRH analogs. In other words, the invention proposes a novel method for protecting said protein active ingredients from digestive enzymes (during gastrointestinal transit). Said method essentially comprises the formulation, in unit or non-unit form, of said active ingredients in free form, with a buffer system, as specified above, in particular selected from those identified above.

[0039] This description also describes a therapeutic treatment method comprising the oral administration of at least one protein active ingredient and / or a method of oral administration of at least one such active ingredient. Characteristically, in said method, said at least one active ingredient is administered (formulated in a solid or liquid composition, unitary or not), in free form, with a buffer system as specified above; that is to say, buffered to a pH as specified above: 4 < pH ≤ 8 (in the case of a liquid form) or capable of being buffered, upon being placed in a liquid medium, to such a pH (in the case of a solid form).The therapies concerned, known to date, are those of the following diseases: diabetes (with reference to the administration of insulin), growth inhibition (with reference to the administration of somatotropin), osteoporosis (with reference to the administration of calcitonin), prostate cancer (with reference to the administration of LHRH analogues).

[0040] We now propose to illustrate the invention by specifying the formula of two buffered insulin tablets according to the invention; and to demonstrate the great interest of said invention by presenting below comparative results of physicochemical tests carried out in vitro and pharmacological tests performed in vivo with insulin. I Formulas

[0041] We prepared, in a well-known way per se(conventional formulation process), using the indicated ingredients in the indicated quantities, two types of tablets of the invention: - dispersible tablets A; and - effervescent tablets B Tablets A : human insulin : 3.5 mg (100 U) trometamol (TRIS) 100 mg calcium phosphate (dicalcium) 250 mg microcrystalline cellulose 250 mg mannitol 250 mg magnesium stearate 10 mg colloidal silica : 1 mg crospovidon 50 mg sodium benzoate 30 mg talc 10 mg citric acid qsp pH 6.5 monosodium citrate Tablet weight: 1 gram Tablets B : human insulin : 3.5 mg (100 U) anhydrous monosodium citrate : 1142.7 mg anhydrous sodium bicarbonate 2076 mg sodium benzoate : 152.60 mg monosodium phosphate 120 mg 96% ethanol qs for granulation demineralized water for a tablet with a theoretical mass of: 3.5 g pH in solution: 6.8. II Tests in vitro

[0042] Tests were carried out in vitro to confirm the metabolic role of pepsin in acidic medium, the metabolic role of trypsin in basic medium and the inactivation of both of these digestive enzymes in buffered medium according to the invention.

[0043] During these various trials, insulin was measured by liquid chromatography. Trial 1' Human insulin solution (100 U)

[0044] + 0.1 N HCl (50 ml) pH 1 + stirring at 37°C 1 h / 2 h / 3 h Time Insulin content Time 0 99,00 U 1 h 99,87 U 2 h 100,13 U 3 h 100,30 U

[0045] In an acidic environment, at pH 1, without pepsin, insulin is stable for more than 3 hours at 37°C. Trial 2' Human insulin solution (100 U)

[0046] + 0.1 N HCl (50 ml) pH 1 + pepsin (160 mg) + stirring at 37°C 1 h Time Insulin content Time 0 0 U 1 h 0 U

[0047] In the presence of the gastric enzyme (pepsin), at pH 1, insulin is immediately degraded. Trial 1 (invention) Human insulin solution (100 U)

[0048] + 0.1 N HCl (50 ml) pH 1 + pepsin (160 mg) + phosphate buffer pH 6.8 (50 ml) + stirring at 37°C 1 h / 2 h / 3 h Time Insulin content Time 0 101,32 U 1 h 101,73 U 2 h 99,72 U 3 h 101,60 U

[0049] In a buffered medium at pH 6.8, pepsin is no longer activated and insulin is stable for more than 3 hours at 37°C. Trial 3' Human insulin solution (100 U)

[0050] + 0.1 N HCl + phosphate buffer pH 8.5 + stirring at 37°C 1 h / 2 h / 3 h Time Insulin content Time 0 100 U 1 h 99,59 U 2 h 100,24 U 3 h 100,48 U

[0051] This trial verified the effectiveness of the buffer and the fact that, in the absence of enzyme, insulin is stable in a basic medium. Trials 2a, 2b, 2c (invention) Human insulin solution (100 U)

[0052] + phosphate buffer pH 6 (test 2a) pH 6.5 (test 2b) pH 6.8 (test 2c) + trypsin 750 U + stirring at 37°C for 1 h / 2 h Time Insulin content pH 6 pH 6.5 pH 6.8 Time 0 100 U 100 U 98 U 1 h 92 U 83 U 56 U 2 h 86 U 72 U 48 U

[0053] In buffered media at the indicated pH levels, the metabolic effect of trypsin is largely attenuated. Trial 4' Human insulin solution (100 U)

[0054] + phosphate buffer pH 8.5 + trypsin 750 U + stirring at 37°C 1 h / 2 h Time Insulin content Time 0 89 U 1 h 14,5 U 2 h 1,5 U

[0055] In the presence of the intestinal enzyme (trypsin), at pH 8.5, insulin is strongly degraded.

[0056] Examination of these results (at basic pH levels) shows that the more the pH increases towards alkalinity, the more trypsin exerts its metabolic effect.

[0057] The optimum point seems to be pH 6.5 (close to neutral) where 2 hours later, despite the presence of trypsin, a significant percentage of insulin is found: 72%. III Tests in vivo

[0058] The hypoglycemic activity of two types of effervescent tablets (with buffer system of the invention: tablets B (see above) and without buffer system of the invention: control effervescent tablets (of the type of tablets B but without buffer)) was studied in rats made diabetic (hyperglycemic) by administration of streptozotocin.

[0059] Streptozotocin, an antibiotic chemically related to nitroureas, has diabetogenic properties by destroying the islets of Langerhans in the pancreas.

[0060] The test is quite familiar to the person skilled in the art. Its principle is summarized below.

[0061] Intraperitoneal administration of 70 mg / kg of streptozotocin in citrate buffer solution to male Wistar rats with an average weight of 200 g causes severe hyperglycemia in the animal after 72 h, associated with polyphagia, polydipsia and polyurea.

[0062] The animals are divided into three groups of eight. Lot 1: Animals normal Non-hyperglycemic animals receiving orally, via an esophageal tube, 30 units of insulin contained in a pH 6.8 buffered tablet (effervescent tablet B (see above)), at a volume of 10 ml / kg. Batch 2: animals diabetics receiving orally, via an esophageal tube, 30 units of insulin contained in an unbuffered tablet (effervescent tablet of the B type but without a buffer), at a volume of 10 ml / kg. Batch 3: animals diabetics receiving orally, via an esophageal tube, 30 units of insulin contained in a pH 6.8 buffered tablet (effervescent tablet B (see above)), at a volume of 10 ml / kg.

[0063] Blood samples are taken every 15 minutes for 3 hours from the animal's tail and blood glucose is assessed using an Abbot glucometer.

[0064] The results are expressed in the tables below. They are expressed in grams of glucose per liter and also in milliequivalents (Table 1), and as a percentage decrease in blood glucose (Table 2). Table 1: Blood glucose (g / l and meq / l) Time in minutes 0 15 30 45 60 75 90 105 120 135 150 165 180 Lot 1 g / l 0,99 ± 0,04 0,99 ± 0,03 0,98 ± 0,05 0,90 ± 0,03 0,85 ± 0,04 0,82 ± 0,05 0,82 ± 0,06 0,84 ± 0,06 0,91 ± 0,05 0,95 ± 0,04 0,99 ± 0,03 1,01 ± 0,02 0,99 ± 0,03 mmeq / l 5,50 ± 0,2 5,50 ± 0,16 5,45 ± 0,3 5 ± 0,16 4,72 ± 0,2 4,56 ± 0,3 4,56 0,33 4,7 ± 0,33 5 ± 0,16 5,3 ± 0,2 5,50 ± 0,16 5,6 ± 0,1 5,5 ± 0,16 Lot 2 g / l 3,94 ± 0,18 3,92 ± 0,16 3,91 ± 0,16 3,88 ± 0,15 3,84 ± 0,16 3,81 ± 0,14 3,82 ± 0,15 3,87 ± 0,13 3,91 ± 0,14 3,94 ± 0,15 3,95 ± 0,15 3,95 ± 0,16 3,92 ± 0,17 mmeq / l 22 ± 1 21,7 ± 0,9 21,7 ± 0,9 21,6 ± 0,8 21,3 ± 0,9 21,2 ± 0,8 21,2 ± 0,8 21,5 ± 0,7 21,7 ± 0,8 21,9 ± 0,8 21,9 ± 0,8 21,9 ± 0,9 21,8 ± 0,9 Lot 3 g / l 3,8 ± 0,5 3,7 ± 0,5 3,2 ± 0,4 2,5 ± 0,3 2,5 ± 0,4 1,76 ± 0,3 1,64 ± 0,4 1,6 ± 0,4 1,65 ± 0,5 1,8 ± 0,5 2,3 ± 0,6 2,78 ± 0,8 3,4 ± 0,8 mmeq / l 21,1 ± 2,8 20,6 ± 2,8 17,8 ± 2,2 14 ± 1,7 11,4 ± 2,2 9,8 ± 1,7 9,1 ± 2,2 8,9 ± 2,2 9,2 ± 2,8 10 ± 2,8 12,8 ± 3,3 15,4 ± 4,5 19 ± 4,5 Table 2: Percentage decrease in blood glucose Time in minutes 15 30 45 60 75 90 105 120 135 150 165 180 Lot 1 0 1 9 14 17 17 15 8 4 0 0 0 Lot 2 0,50 0,75 1,5 2,5 3,3 3 1,8 0,75 0,50 0 0 0 Lot 3 1 16 33 46 54 56 57 57 52 39 27 11

[0065] The results from Table 2 have been transferred to the single attached figure (percentage decrease in blood glucose over time (expressed in minutes)): The curve -■- shows the results of batch 1, the curve --◆-- shows the results of batch 2, the curve -▲- shows the results of batch 3.

[0066] An examination of the results shows: In normal (non-hyperglycemic) animals (group 1), administration of buffered insulin resulted in a slight decrease in blood glucose levels within 45 minutes, reaching a maximum at 75 minutes. Blood glucose returned to normal levels by 150 minutes. These animals, with intact pancreases, compensated by secreting glucagon, which is hyperglycemic. In diabetic animals (group 2), administration of unbuffered insulin resulted in a very slight, insignificant decrease in blood glucose. Throughout the experiment, these animals maintained very high blood glucose levels. In diabetic animals (group 3), administration of buffered insulin resulted in a highly significant decrease in blood glucose levels within 45 minutes, reaching a maximum at 105 minutes. A gradual increase in blood glucose was then observed. All animals showed a significant improvement, although they did not return to normal blood glucose levels due to the severity of their diabetes.

[0067] These results show that the buffer system used preserved the hypoglycemic activity of orally administered insulin (which is entirely consistent with the results obtained). in vitro ) and confirm good bioavailability of said insulin.

[0068] The results, both in vitro that in vivo demonstrate the effectiveness of the buffer system in preserving insulin activity: in vitro, In an acidic, unbuffered medium, insulin is metabolized by pepsin (trial 2'). In a buffered medium at pH 6.8, pepsin is no longer active, and therefore 100% of insulin is recovered after 3 hours (trial 1). In a basic medium, insulin is metabolized by trypsin (trial 4'). In buffered media at pH 6, 6.5, and 6.8, the activity of trypsin is inhibited, or more or less reduced. in vivoThe unbuffered preparation has virtually no activity. The buffered preparation, on the other hand, has significant hypoglycemic activity.

[0069] In all the trials, both in vitro that in vivo Human insulin was used. It is clear that the results obtained are applicable to all insulin analogues.

[0070] In light of these results, the full potential of the present invention is readily apparent. This potential has been confirmed by preliminary human trials.

Claims

1. Composition, in liquid or solid form, containing: at least one protein active ingredient in free form, as well as, for a liquid, a system capable of buffering it to a pH greater than 4 and less than or equal to 8 or, for a solid, a system that exerts, when it is placed in a liquid medium, a buffering effect between a pH greater than 4 and a pH less than or equal to 8, for use as a medicament in the oral treatment of a disease via gastrointestinal tract, said at least one protein active ingredient is chosen from (i) insulin, analogues thereof and derivatives thereof, (ii) somatotropin, (iii) calcitonin, and (iv) L.H.R.H. analogues.

2. Composition for use according to claim 1, obtainable by the formulation of said at least one protein active ingredient in free form, with a system capable of buffering it, in liquid form, to a pH greater than 4 and less than or equal to 8 or, in solid form, with a system that exerts, when said solid form is placed in a liquid medium, a buffer effect between a pH greater than 4 and a pH less than or equal to 8.

3. Composition for use according to any one of claims 1 or 2, characterized in that the buffer pH is between 4.5 and 7.5, very advantageously between 5 and 7.

4. Composition for use according to any one of claims 1 to 3, characterized in that said at least one protein active ingredient is selected among insulin, analogues thereof and derivatives thereof.

5. Composition for use according to any one of claims 1 to 4, characterized in that said system, responsible for the buffer effect, is a buffer chosen among phosphate, acetate, maleate, phthalate, succinate, citrate, imidazole, tetrabutylammonium, trihydroxymethylaminomethane, tris-glycine, barbitol, tris-EDTA BSA, copper sulfate and zwitterionic buffers.

6. Composition for use according to any one of claims 1 to 5, characterized in that it is formulated in unit form.

7. Composition for use according to any one of claims 1 to 6, characterized in that it is, as a liquid, in the form of a solution, suspension or syrup or, as a solid, in the form of tablets, notably dispersible, orodispersible or effervescent tablets, capsules, powder, effervescent powder, granules, effervescent granules or a lyophilisate.

8. Composition for use according to any one of claims 1 to 7, characterized in that it is in the form of solid pharmaceutical preparations, notably dispersible tablets or effervescent tablets.

9. Composition for use according to any one of claims 1 to 5, characterized in that said system responsible for the buffer effect is formulated separately from said at least one protein active ingredient.

10. Use of a buffer system for the manufacture of a pharmaceutical composition intended for the oral treatment of diabetes via the gastrointestinal tract; said pharmaceutical composition, which may be liquid or solid, containing at least one active protein ingredient selected from insulin, analogues thereof and derivatives thereof, in free form, as well as said buffer system; said buffer system being capable of buffering said liquid pharmaceutical composition to a pH between 5 and 7 or being capable of exerting, when said solid pharmaceutical composition is placed in a liquid medium, a buffering effect at a pH between 5 and 7; said buffer system thus protecting said at least one protein active ingredient in the gastrointestinal tract.

11. Use of a buffer system for the manufacture of a pharmaceutical composition intended for the treatment of a disease by oral administration via the gastrointestinal tract; said pharmaceutical composition, liquid or solid, containing at least one active protein ingredient in free form as well as said buffer system; said buffer system being capable of for buffering said liquid pharmaceutical composition at a pH greater than 4 and less than or equal to 8 or being capable of exerting, when said solid pharmaceutical composition is placed in a liquid medium, a buffering effect between a pH greater than 4 and less than or equal to 8; said buffer system thus protecting said at least one protein active ingredient in the gastrointestinal tract, said at least one protein active ingredient being selected from (i) insulin, analogues thereof and derivatives thereof, (ii) somatotropin, (iii) calcitonin, and (iv) L.H.R.H. analogues.