Pharmaceutical composition for use in treatment of diabetes

Abstract: Pharmaceutical composition which comprises an insulin sensitivity enhancer in combination with other antidiabetics differing from the enhancer in the mechanism of action, which shows a potent depressive effect on diabetic hyperglycemia and is useful for prophylaxis and treatment of diabetes.

Description: FIELD OF THE INVENTION The present invention relates to a pharmaceutical composition comprising an insulin sensitivity enhancer selected from pioglitazone, 5-[[4-[2-(methyl-2-pyridylamino)ethoxy]phenyl]methyl]-2, 4-thiazolidinedione or a pharmacologically acceptable salt thereof in combination with metformin. BACKGROUND OF THE INVENTION Recent years, the pathology of diabetes has become more and more understood and, in parallel, drugs specific for the respective pathologic states have been developed. Accordingly a variety of drugs having new mechanisms of action have appeared one after another. Insulin sensitivity enhancers are also known as insulin resistance deblockers because they have the action to normalize the impaired insulin receptor function, and are gathering much attention in these years. Regarding such insulin sensitivity enhancers, a very useful compound such as pioglitazone has been developed [Fujita et al., Diabetes, 32 , 804-810, 1983, JP-A S55(1980)-22636 (EP-A 8203), JP-A S61(1986)-267580 (EP-A 193256)]. Pioglitazone restores the impaired insulin receptor function to normalize the uneven distribution of glucose transporters in cells, the cardinal enzyme systems associated with glycometabolism, such as glucokinase, and enzyme systems associated with lipidmetabolism, such as lipoprotein lipase. As the results, insulin resistance are deblocked to improve glucose tolerance, and lower the plasma concentrations of neutral lipids and free fatty acids. Since these actions of pioglitazone are comparatively gradual and the risk of side effect in long-term administration is also low, this compound is useful for obese patients who are presumed to be highly insulin-resistant. Also, insulin sensitivity enhancers such as CS-045, thazolidinedione derivatives and substituted thiazolidinedione derivatives are reported to be used in combination with insulin [JP-A H4(1992)-66579, JP-A H4(1992)-69383, JP-A H5(1993)-202042]. However, the pharmaceutical composition having a specific combination of the present invention is unknown. Diabetes is a.chronic disease with diverse pathologic manifestations and is accompanied by lipidmetabolism disorders and circulatory disorders as well as glycometabolism disorders. As the results, diabetes tends to progress entailing various complications in many cases. Therefore, it is necessary to select the drug of choice for the prevailing disease state in each individual case. However, this selection is often difficult in clinical settings because single use of each individual drug can not bring sufficient effects in some disease states and there are various problems such as side effect which is caused by an increased dose or a long-term administration. SUMMARY OF THE INVENTION In view of the above state of the art, the inventors of the present invention did much research to develop antidiabetics which would not virtually cause adverse reactions even on long-term administration and could be effective for a large cohort of the diabetic population. As a consequence, they discovered that the above object can be accomplished by using an insulin sensitivity enhancer, such as the drug described above, in combination with metformin, and accordingly have perfected the present invention. The present invention, therefore, relates to a pharmaceutical composition which comprises an insulin sensitivity enhancer selected from pioglitazone, 5-[[4-[2-(methyl-2-pyridylamino)ethoxy]phenyl]methyl]-2, 4-thiazolidinedione or a pharmacologically acceptable salt thereof in combination with metformin. The insulin sensitivity enhancer is especially preferably pioglitazone. The pharmacologically acceptable salt of the insulin sensitivity enhancer is exemplified by salts with inorganic bases, salts with organic bases, salts with inorganic acids, salts with organic acids, and salts with basic or acidic amino acids. Preferable examples of salts with inorganic bases include salts with alkali metals such as sodium, potassium, etc., salts with alkaline earth metals such as calcium, magnesium, etc., and salts with'aluminum, ammonium, etc. Preferable examples of salts with organic bases include salts with trimethylamine., triethylamine, pyridine, picoline, ethanolamine, diethanolamine, triethanolamine, dicyclohexylamine, N,N-dibenzylethylenediamine, etc. Preferable examples of salts with inorganic acids include salts with hydrochloric acid, hydrobromic acid, nitric acid, sulfuric acid, phosphoric acid, etc. Preferable examples of salts with organic acids include salts with formic acid, acetic acid, trifluoroacetic acid, fumaric acid, oxalic acid, tartaric acid, maleic acid, citric acid, succinic acid, malic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, etc. Preferable examples of salts with basic amino acids include salts with arginine, lysine, ornithine, etc., and preferable examples of salts with acidic amino acids include salts with aspartic acid, glutamic acid, etc. When the insulin sensitivity enhancer in pioglitazone, the pharmacologically acceptable salt is preferably a salt with an inorganic acid, more preferably a salt with hydrochloric acid. Especially, pioglitazone is preferably used in the form of salt with hydrochloric acid. The pharmaceutical composition comprising the insulin sensitivity enhancer in combination with metformin can be respectively put to use by mixing the respective active components either all together or independently with a physiologically acceptable carrier, excipient, binder, diluent, etc. and administering the mixture or mixtures either orally or non-orally as a pharmaceutical composition. When the active components are formulated independently, the respective formulations can be extemporaneously admixed using a diluent or the like and administered or can be administered independently of each other, either concurrently or at staggered times to the same subject. The dosage form for said pharmaceutical composition includes such oral dosage forms as granules, powders, tablets, capsules, syrups, emulsions, suspensions, etc. and such non-oral dosage forms as injections (e.g. subcutaneous, intravenous, intramuscular and intraperitoneal injections), drip infusions, external application forms (e.g. nasal spray preparations, transdermal preparations, ointments, etc.), and suppositories (e.g. rectal and vaginal suppositories). These dosage forms can be manufactured by the per se known technique conventionally used in pharmaceutical procedures. The specific manufacturing procedures are as follows. To manufacture an oral dosage form, an excipient (e.g. lactose, sucrose, starch, mannitol, etc.), a disintegrator (e.g. calcium carbonate, carboxymethylcellulose calcium, etc.), a binder (e.g. α-starch, gum arabic, carboxymethylcellulose, polyvinylpyrrolidone, hydroxypropylcellulose, etc.), and a lubricant (e.g. talc, magnesium stearate, polyethylene glycol 6000, etc.), for instance, are added to the active component or components and the resulting composition is compressed. Where necessary, the compressed product is coated, by the per se known technique, for masking the taste or for enteric dissolution.or sustained release. The coating material that can be used includes, for instance, ethylcellulose, hydroxymethylcellulose, polyoxyethylene glycol, cellulose acetate phthalate, hydroxypropylmethylcellulose phthalate, and Eudragit (Rohm & Haas, Germany, methacrylic-acrylic copolymer). Injections can be manufactured typically by the following procedure. The active component or components are dissolved, suspended or emulsified in an aqueous vehicle (e.g. distilled water, physiological saline, Ringer's solution, etc.) or an oily vehicle (e.g. vegitable oil such as olive oil, sesame oil, cottonseed oil, corn oil, etc. or propylene glycol) together with a dispersant (e.g. Tween 80 (Atlas Powder, U.S.A.), HCO 60 (Nikko Chemicals), polyethylene glycol, carboxymethylcellulose, sodium alginate, etc.), a preservative (e.g. methyl p-hydroxybenzoate, propyl p-hydroxybenzoate, benzyl alcohol, chlorobutanol, phenol, etc.), an isotonizing agent (e.g. sodium chloride, glycerol, sorbitol, glucose, inverted sugar, etc.) and other additives. If desired, a solubi lizer (e.g. sodium salicylate, sodium acetate, etc.), a stabilizer (e.g. human serum albumin), a soothing agent (e.g. benzalkonium chloride, procaine hydrochloride, etc.) and other additives can also be added. A dosage form for external application can be manufactured by processing the active component or components into a solid, semi-solid or liquid composition. To manufacture a solid composition, for instance, the active component or components, either as they are or in admixture with an excipient (e.g. lactose, mannitol, starch, microcrystalline cellulose, sucrose, etc.), a thickener (e.g. natural gums, cellulose derivatives, acrylic polymers, etc.), etc., are processed into powders. The liquid composition can be manufactured in substantially the same manner as the injections mentioned above. The semi-solid composition is preferably provided in a hydrous or oily gel form or an ointment form. These compositions may optionally contain a pH control agent (e.g. carbonic acid, phosphoric acid, citric acid, hydrochloric acid, sodium hydroxide, etc.), and a preservative (e.g. p-hydroxybenzoic acid esters, chlorobutanol, benzalkonium chloride, etc.), among other additives. Suppositories can be manufactured by processing the active component or components into an oily or aqueous composition, whether solid, semi-solid or liquid. The oleaginous base that can be used includes, for instance, higher fatty acid glycerides [e.g. cacao butter, Witepsols (Dinamit-Nobel), etc.], medium-chain fatty acids [e.g. Migriols (Dinamit-Nobel), etc.], vegetable oils (e.g. sesame oil, soybean oil, cottonseed oil, etc.), etc. The water-soluble base includes, for instance, polyethylene glycols, propylene glycol, etc. The hydrophilic base includes, for instance, natural gums, cellulose derivatives, vinyl polymers, and acrylic polymers, etc. The pharmaceutical composition of the present invention is low in toxicity and can be safely used in mammals (e.g. humans, mice, rats, rabbits, dogs, cats, bovines, horses, swines, monkeys). The dosage of the pharmaceutical composition of the present invention may be appropriately determined with reference to the dosages recommended for the respective active components and can be selected appropriately according to the recipient, the recipient's age and body weight, current clinic al status, administration time, dosage form, method of administration, and combination of the active components, among other factors. For example, the dosage of the insulin sensitivity enhancer for an adult can be selected from the clinical oral dose range of 0.01 to 10 mg/kg body weight (preferably 0.05 to 10 mg/kg body weight, more preferably 0.05 to 5 mg/kg body weight) or the clinical parenteral dose range of 0.005 to 10 mg/kg body weight (preferably 0.01 to 10 mg/kg body weight, more preferably 0.01 to 1 mg/kg body weight). The other active component or components having different modes of action for use in combination can also be used in dose ranges selected by referring to the respective recommended clinical dose ranges. The preferred frequency of administration is 1 to 3 times a day. The proportions of the active components in the pharmaceutical composition of the present invention can be appropriately selected according to the recipient, the recipient's age and body weight, current clinical status, administration time, dosage form, method of administration, and combination of active components, among other factors. The pharmaceutical composition of the present invention shows a marked synergistic effect compared with administration of either active component alone. For example, compared with cases in which each of these active components was administered to diabetic Wistar fatty rats with genetical obsesity, administration of these active components in combination resulted in marked improvements in both hyperglycemia and reduced glucose tolerance. Thus, the pharmaceutical composition of the present invention lowers blood glucose in diabetics more effectively than it is the case with administration of each component drug alone and, therefore, can be used advantageously for the prophylaxis and treatment of diabetic complications. Furthermore, since the pharmaceutical composition of the present invention develops sufficient efficacy with reduced doses as compared with the administration of any one of the active components alone, the side effects of the respective components (e.g. gastrointestinal disorders such as diarrhea, etc.) can be reduced. The pharmaceutical composition of the present invention can be prepared in an analagous manner to the following reference formulations. Reference Example 1 Capsules (1) Pioglitazone hydrochloride 30 mg (2) Voglibose 0.2 mg (3) Lactose 60 mg (4) Microcrystalline cellulose 79.8 mg (5) Magnesium stearate 10 mg Total 180 mg The whole amounts of (1), (2), (3) and (4) and half the amount of (5) are mixed well and granulated in the conventional manner. Then, the balance of (5) is added and, after mixing, the whole composition is filled in a gelatin hard capsule shell. Reference Example 2 Tablets (1) Pioglitazone hydrochloride 10 mg (2) Glibenclamide 1.25 mg (3) Lactose 86.25 mg (4) Corn starch 20 mg (5) polyethylene glycol 2.5 mg (6) Hydroxypropylcellulose 4 mg (7) Carmellose calcium 5.5 mg (8) Magnesium stearate 0.5 mg 130 mg (per tablet) The whole amounts of (1), (2), (3), (4), and (5), 2/3 amounts of (6) and (7), and 1/2 amount of (8) are mixed well and granulated in the conventional manner. Then, the balances of (6), (7) and (8) are added to the granules, which is mixed well and the whole composition is compressed with a tablet machine. The adult dosage is 3 tablets/day, to be taken in 1 to 3 divided doses. Reference Example 3 Capsules (1) Pioglitazone hydrochloride 10 mg (2) Epalrestat 50 mg (3) Lactose 55 mg (4) Microcrystalline cellulose 55 mg (5) Magnesium stearate 10 mg Total 180 mg The whole amounts of (1), (2), (3) and (4) and 1/2 amount of (5) are mixed well and granulated in the conventional manner. Then, the balance of (5) is added and the whole composition is filled in gelatin capsule shell. The adult dosage is 3 capsules/day, to be taken in 1 to 3 divided doses. The pharmaceutical composition of the present invention shows a potent depressive effect on diabetic hyperglycemia and is useful for prophylaxis and treatment of diabetes. Moreover, this pharmaceutical composition is useful for prophylaxis and treatment of diabetic complications such as diabetic neuropathy, nephropathy, retinopathy, macroangiopathy, and osteopenia. In addition, by appropriately selecting the kinds of component drugs, administration route, dosage, etc. according to clinical status, stable hypoglycemic efficacy in long-term therapy can be expected with an extremely low risk of side effect.

Claims: Pharmaceutical composition which comprises an insulin sensitivity enhancer selected from pioglitazone, 5-[[4-[2-(methyl-2-pyridylamino)ethoxy]phenyl]methyl]-2, 4-thiazolidinedione or a pharmacologically acceptable salt thereof in combination with metformin. Pharmaceutical composition according to claim 1, wherein the insulin sensitivity enhancer and the metformin are formulated altogether. Pharmaceutical composition according to claim 1, wherein the insulin sensitivity enhancer and the metformin are formulated independently for administration concurrently or at staggered times to the same subject. Pharmaceutical composition according to any one of claim 1 to 3, wherein the insulin sensitivity enhancer is pioglitazone or its hydrochloride. Pharmaceutical composition according to any one of claim 1 to 3, wherein the insulin sensitivity enhancer is 5-[[4-[2-(methyl-2-pyridylamino)ethoxy]phenyl]methyl]-2,4-thiazolidinedione or a pharmaceutically acceptable salt thereof. Pharmaceutical composition according to any one of claim 1 to 3, which is for prophylaxis or treatment of diabetes. Pharmaceutical composition according to any one of claim 1 to 3, which is for prophylaxis or treatment of diabetic complications. Use of an insulin sensitivity enhancer selected from pioglitazone, 5-[[4-[2-(methyl-2-pyridylamino)ethoxy]phenyl] methyl]-2, 4-thiazolidinedione or a pharmacologically acceptable salt thereof for the manufacture of pharmaceuticals for reducing the amount of metformin to be administered to a diabetic patient. Use of an insulin sensitivity enhancer selected from pioglitazone, 5-[[4-[2-(methyl-2-pyridylamino)ethoxy]phenyl] methyl]-2, 4-thiazolidinedione or a pharmacologically acceptable salt thereof for the manufacture of pharmaceuticals for reducing the side effects of metformin to be administered to a diabetic patient. Use of an insulin sensitivity enhancer selected from pioglitazone, 5-[[4-[2-(methyl-2-pyridylamino)ethoxy]phenyl] methyl]-2, 4-thiazolidinedione or a pharmacologically acceptable salt thereof in combination with metformin for the manufacture of pharmaceuticals for the prophylaxis and treatment of diabetes. Use of an insulin sensitivity enhancer selected from pioglitazone, 5-[[4-[2-(methyl-2-pyridylamino)ethoxy]phenyl] methyl]-2, 4-thiazolidinedione or a pharmacologically acceptable salt thereof in combination with metformin for the manufacture of pharmaceuticals for the prophylaxis and treatment of diabetic complications. Use according to any one of claims 8 to 11, wherein the insulin sensitivity enhancer is pioglitazone or its hydrochloride. Use according to any one of claims 8 to 11, wherein the insulin sensitivity enhancer is 5-[[4-[2-(methyl-2-pyridylamino)ethoxy]phenyl]methyl]-2,4-thiazolidinedione or a pharmaceutically acceptable salt thereof. Use according to any of claims 10 or 11, wherein the insulin sensitivity enhancer and the metformin are to be administered concurrently to the same subject. Use according to any of claims 10 or 11, wherein the insulin sensitivity enhancer and the metformin are to be administered at staggered times to the same subject. Use of an insulin sensitivity enhancer selected from pioglitazone, 5-[[4-[2-(methyl-2-pyridylamino)ethoxy]phenyl]methyl]-2,4-thiazolidinedione or a pharmacologically acceptable salt thereof for the manufacture of pharmaceuticals comprising a combination of an insulin sensitivity enhancer selected from pioglitazone, 5-[[4-[2-(methyl-2-pyridylamino)ethoxy]phenyl]methyl]-2,4-thiazolidinedione, or a pharmacologically acceptable salt thereof, and metformin for the prophylaxis and treatment of diabetes. Use of an insulin sensitivity enhancer selected from pioglitazone, 5-[[4-[2-(methyl-2-pyridylamino)ethoxy]phenyl]methyl]-2,4-thiazolidinedione or a pharmacologically acceptable salt thereof for the manufacture of pharmaceuticals comprising a combination of an insulin. sensitivity enhancer selected from pioglitazone, 5-[[4-[2-(methyl-2-pyridylamino)ethoxy]phenyl]methyl]-2,4-thiazolidinedione, or a pharmacologically acceptable salt thereof, and metformin for the prophylaxis and treatment of diabetic complications. Use according to claim 16 or claim 17, wherein the insulin sensitivity enhancer and the metformin are formulated altogether. Use according to claim 16 or claim 17, wherein the insulin sensitivity enhancer and the metformin are formulated independently for administration concurrently or at staggered times to the same subject. Use of metformin for the manufacture of pharmaceuticals comprising a combination of an insulin sensitivity enhancer selected from pioglitazone, 5-[[4-[2-(methyl-2-pyridylamino)ethoxy]phenyl]methyl]-2,4-thiazolidinedione, or a pharmacologically acceptable salt thereof, and metformin for the prophylaxis and treatment of diabetes. Use of metformin for the manufacture of pharmaceuticals comprising a combination of an insulin sensitivity enhancer selected from pioglitazone, 5-[[4-[2-(methyl-2-pyridylamino)ethoxy]phenyl]methyl]-2,4-thiazolidinedione, or a pharmacologically acceptable salt thereof, and metformin for the prophylaxis and treatment of diabetic complications. Use according to claim 20 or claim 21, wherein the insulin sensitivity enhancer and the metformin are formulated altogether. Use according to claim 20 or claim 21, wherein the insulin sensitivity enhancer and the metformin are formulated independently for administration concurrently or at staggered times to the same subject.

Inventors: IKEDA HITOSHI, ODAKA HIROYUKI, SOHDA TAKASHI, IKEDA, HITOSHI, ODAKA, HIROYUKI, SOHDA, TAKASHI
Applicants: TAKEDA CHEMICAL INDUSTRIES LTD, TAKEDA CHEMICAL INDUSTRIES, LTD.
Application year: 1996
Main classification: A61K31
IPC codes: A61P5, A61K31, A61K9, A61P3, C07D263, A61K45, A61P43, C07D277