PROPHYLACTIC AND CURING COMPOSITION CONTAINING A 8-CHLOROBENZOTHIAZEPINE COMPOUND AND ITS USE

Abstract: There are disclosed a prophylactic and curing composi­ tion for arteriosclerosis, which comprises as an active in­ gredient a 8-chloro-1,5-benzothiazepine derivative represent­ ed by the formula: wherein R¹, R², R³ and R⁴ each represent lower alkyl groups, or a pharmaceutically acceptable salt thereof, and a use of the compound (I) or a pharmaceutcally acceptable salt thereof for preparing a prophylactic and curing composition for arter­ iosclerosis.

Description: The invention relates to the use of (+)-cis-2-(4-methoxyphenyl)-3-acetoxy-5-[2-dimethylamino)ethyl]-8-chloro-2,3-dihydro-1,5-benzothiazepin-4-(5H)-one represented by the formula or a pharmaceutically acceptable salt thereof for preparing a prophylactic and curing composition for arteriosclerosis. 2-(4-Methoxyphenyl)-3-acetoxy-5-[2-(dimethyl amino)ethyl)-8-chloro-2,3-dihydro-1,5-benzothiazepin-4(5H)-one is a known compound, and it has been shown to have excellent hypotensive activity and/or cerebral and coronary vasodilating activity (Japanese Unexamined Patent Publication No. 225174/1984). However, in the prior art, it has never been shown that this compound shows anti-arteriosclerosis activity. Arteriosclerosis is pathologically classified into the three groups of atherosclerosis, Mönkeberg's sclerosis (medial sclerosis) and arteriolosclerosis. Atherosclerosis is characterized by lipid deposition and plaque formation in the intima of e.g., coronary artery, basilar artery, renal artery, thoracic aorta or abdominal aorta. Mönkeberg's sclerosis is frequently observed in medium-sized arteries in extremities, such as e.g., femoral artery, and characterized by calcification of arterial media. Arteriolosclerosis is a sclerotic change which is observed in arterioles in e.g. the kidney, adrenal gland, spleen, ovary or pancreas. In recent years, advanced studies have been made in to arteriosclerosis, and it has been considered that non-limited growth of medial smooth muscle cells in the intima of blood vessels and abnormal accumulation of cholesterol within cells can be the causes for such arteriosclerosis. The relationship between such causes and prostacyclin (PGI₂) is now of interest. For example, when a rabbit is fed with a cholesterol-rich diet, it has been shown that prostacyclin producing ability of artery is lowered together with the progress of arteriosclerosis of said rabbit. It is also known that prostacyclin producing ability is lowered at the arteriosclerotic lesion site to a level half or lower of that at normal site [Gendai Iryo (Modern Medical Treatment), 12 , 909(1980)]. On the other hand, Hajjar et al report that addition of prostacyclin to a culture system of medial smooth muscle cells from rabbit aorta increases ACEH (Acid cholesteryl ester hydrolase) activity of the cells, whereby deposition of cholesterol within cells is inhibited [Journal of Clinical Investigation, 70 , 479 (1982)]. Further, it is also reported that in medial smooth muscle cells from arteriosclerotic lesions that addition of prostacyclin in a culture system lowers the cholesterol content in said cells [Lancet, 2 , 521 (1983)]. Diltiazem is a known medicament for the treatment of atheriosclerosis (GB-A-2 135 192). Arteriosclerosis, Vol. 6, 1986, pp. 237-241 confirm this and show that this property can be extended to Ca++-antagonists. Diltiazem is also known to possess an antilipidemic activity according to (4) GB-A-2 141 027. Furthermore it is shown in EP-A-0 158 339 that 8-chlorobenzothiazepine compounds and the diltiazem group exhibit a common pharmacological profile. The present invention, in view of the state of the art as described above, is intended to provide a novel prophylactic and curing agent for arteriosclerosis having the activity of potentiating prostacyclin producing ability of medial smooth muscle cells of blood vessel and also having anti-arteriosclerosis activity. The present invention comprises the use of (+)-cis-2-(4-methoxyphenyl)-3-acetoxy-5-[2-dimethylamino)ethyl]-8-chloro-2,3-dihydro-1,5-benzothiazepin-4-(5H)-one represented by the formula or a pharmaceutically acceptable salt thereof for preparing a prophylactic and curing composition for atherosclerosis, Mönkeberg's sclerosis or arteriosclerosis. The compound (I) which is the active ingredient of the present invention potentiates markedly the prostacyclin producing ability of medial smooth muscle cells of blood vessels and also has excellent anti-arteriosclerosis activity. For example, when (+)-cis-2-(4-methoxyphenyl)-3-acetoxy-5-[2-(dimethylamino)ethyl]-8-chloro-2,3-dihydro-1,5-benzothiazepin-4(5H)-one was added to cultured rat aortic smooth muscle cells for examination of prostacyclin producing ability of said cells, the above compound exhibited excellent activity for potentiating prostacyclin producing ability. Also, when the effect of (+)-cis-2-(4-(4-methoxyphenyl)-3-acetoxy-5-[2-(dimethylamino)ethyl]-8-chloro-2,3-dihydro-1,5-benzothiazepin-4(5H)-one in experimental atherosclerosis in rabbits and Mönkeberg's sclerosis in rats was examined, the above compound exhibited excellent ameliorating effect on either type of arteriosclerosis. Thus, the medicament of the present invention can be used for prophylaxis or treatment of various arteriosclerosis such as atherosclerosis, Mönkeberg's sclerosis (medial sclerosis) and arteriolosclerosis. The above compound (I) which is the active ingredient in the medicament of the present invention can be used for pharmaceutical uses in the form of either a free base or a pharmaceutically acceptable acid addition salt thereof. Examples of such pharmaceutically acceptable acid addition salts may include inorganic acid addition salts such as hydrochloride, hydrobromide, hydroiodide, perchlorate, sulfate or phosphate or organic acid addition salts such as oxalate, maleate, fumarate, succinate, methanesulfonate or 2-(4-hydroxybenzoyl) benzoate. The compound (I) or a pharmaceutically acceptable acid addition salt thereof can be administered both orally and parenterally together with excipients suitable for oral or parenteral administration. The medicament of the present invention can be formed into a suitable preparation by use of pharmaceutical carriers conventionally used in either oral or parenteral administration. Such pharmaceutical carriers may include, for example, binding agents (syrup, gum arabic, gelatin, sorbitol, tragacanth gum and polyvinylpyrrolidone, excipients (lactose, sucrose, corn starch, potassium phosphate, sorbitol and glycine), lubricants (magnesium stearate, talc, polyethylene glycol and silica, disintegrators (potato starch) and wetting agents (sodium laurylsulfate). Preparation forms may be, e.g., tablets, pills, powders, capsules or granules. Further, for parenteral administration, the medicament may be used in the form of an injection or instillation by use of distilled water for injection, physiological saline, aqueous glucose solution, etc., and also in the form a suspension, dispersion or emulsion which is prepared with the use of glycerine, propylene glycol, simple syrup, ethanol, fatty oils, ethylene glycol or sorbitol. The dose of the compound (I) or its acid addition salt which is the active ingredient of the present invention may vary according to the age and body weight of the patient and the kind and severity of the disease, but is generally about 0.05 to 60 mg/kg/day, preferably about 0.05 to 10 mg/kg/day, particularly preferably 0.5 to 10 mg/kg/day in the case of oral administration and about 0.05 to 2 mg/kg/day in the case of parenteral administration. The compound (I) which is the active ingredient of the present invention can be prepared according to, for example, the method disclosed in Japanese Unexamined Patent Publication No. 225174/1984 (which corresponds to U.S. Patent No. 4,567,175). EXAMPLES The present invention is described in more detail by referring to the following Experimental examples and Examples. Experimental example 1 (Prostacyclin production promoting activity for aortic smooth muscle cells) After rat aortic smooth muscle cells (hereinafter called SMC) were grown to confluence in culture dish by using growth medium, the growth medium was removed and preincuvation was conducted with addition of a medium for assay at 37 °C for 15 minutes. Then, the medium was removed and a medium for assay containing a test compound was freshly added, followed by cultivation at 37 °C in 5 % CO₂ - 95 % air for 24 hours. After completion of the cultivation, the prostacyclin production promoting activity of the test compound was examined by assaying the stable prostacyclin metabolite (6-KetoPGF₁α) existing in the supernatant according to radioimmunoassay. As the test compound, (+)-cis-2-(4-methoxyphenyl)-3-acetoxy-5-[2-(dimethylamino)ethyl]-8-chloro-2,3-dihydro-1,5-benzothiazepin-4(5H)-one maleate was employed. (Note) The respective media used in the above experiment had the following compositions. Growth medium for proliferation: Eagle's Minimum Essential Medium + 10 % fetal calf serum Medium for assay: Eagle's Minimum Essential Medium + 10 mM N-2-hydroxyethylpiperazine-N-2-ethanesulfinic acid (pH 7.4) <Results> The results are shown in the following Table 1. It was recognized that the prostacyclin producing ability was increased to about 1.8-fold in the case of adding the test compound as compared with the case of no addition. Concentration of test compound added Amount of 6-KetoPGF₁α produced (pg/24h/1 x 10⁶ cells) No addition 129 ± 20 1 x 10⁻⁵ M 226 ± 32 Experimental example 2 (Effect on atherosclerosis) Rabbits (male, weight: about 2.4 Kg, one group: 10 rabbits) were fed with a lipid-rich diet (prepared by adding cholesterol (0.5 %) and soybean oil (3 %) to normal diet) for 12 weeks. On the other hand, in order to examine the effect of the test compound on the arteriosclerosis in the aorta induced under such experimental conditions, an aqueous solution of the test compound (30 mg/kg) was administered to the animals with a stomach tube once a day at a fixed time simultaneously with initiation of dieting with the lipid-rich diet. Twelve weeks after initiation of the experiment, rabbits were killed under anesthesia (ether and pentobarbital were used in combination), and the proportion of the atheroma in the intima of the arotic arch and thoracic aorta (atheroma formation ratio) was examined. As the test compound, (+)-cis-2-(4-methoxyphenyl)-3-acetoxy-5-[2-(dimethylamino)ethyl]-8-chloro-2,3-dihydro-1,5-benzothiazepin-4(5H)-one maleate was used. <Results> The results are shown in Table 2, and it can be clearly seen that in the group administered the test compound atheroma formation ratio is lower compared with that in the non-administration group. This effect in the group administered the test compound suggests that the atheromatous changes, namely deposition of cholesterol in the blood vessel wall, atheroma formation accompanied with an increase in connective tissue filters in the intima and subsequent ulcer formation by breaks of said atheroma, are inhibited by the prostacyclin production potentiating effect of the compound of the present invention. Atheroma formation rate (%) Test compound non-administration group 51.2 ± 5.6 Test compound administration group 38.4 ± 5.8 Experimental example 3 (Effect on Mönkeberg's sclerosis) Spontaneously hypertensive rats (male, age: 12 weeks, one group: 14 - 15 rats) were fed with a lipid-rich diet (prepared by adding cholesterol (3 %), hydrogenated cotton seed oil (7 %), cholic acid (0.5 %) and thiouracil (0.3 %) to normal diet) for 7 days, and further, for first four days, vitamin D₂ (8 mg/kg) was administered to the animals with a stomach tube in the form of a solution in olive oil (2 ml/kg) once at a fixed time every day. In order to examine the effect of the test compound on Mönkeberg's sclerosis of the aorta induced under such experimental conditions, an aqueous solution of the test compound was administered to the animals with a stomach tube one hour and 7 hours after the administration of vitamin D₂ for 4 days, and further administration of the test compound alone was continued twice per day for the next 3 days. On the 7th day after initiation of the experiment, the rats were killed under ether anesthesia and the lesions were examined. As the test compound (+)-cis-2-(4-methoxyphenyl)-3-acetoxy-5-[2-(dimethylamino)ethyl]-8-chloro-2,3-dihydro-1,5-benzothiazepin-4(5H)-one maleate was used. <Results> The results are shown in Table 3, and it can be clearly seen that the incidence of lesions is lowered in the group treated with the test compound. Lesions Dose of test compound 0 30mg x 2/kg/day Subdural haemorrhage 11/14 8/15 Periaortic haemorrhage 7/14 3/15 Subcutaneous haemorrage 7/14 3/15 (In the numerical values in the Table, denominator indicates the number of rats used in the experiment, and numerator the number of rats in which lesions were recognized.) Example 1 (Tablet) (+)-Cis-2-(4-methoxyphenyl)-3-acetoxy-5-[2-(dimethylamino)ethyl]-8-chloro-2 , 3-dihydro-1,5-benzothiazepin-4(5H)-one maleate 45.0 g Corn starch 20.1 g Lactose 82.4 g Polyvinylpyrrolidone 3.0 g Crystalline cellulose 38.0 g Magnesium stearate 1.5 g Total 190.0 g The medicament, lactose and corn starch were mixed with an alcohol solution of polyvinylpyrrolidone and granulated by kneading according to the wet granulation method, followed by drying to be formed into granules. Subsequently, magnesium stearate and crystalline cellulose were added to the granules and the mixture is compressed to obtain tablets of 8 mm in diameter and 190 mg in weight. Example 2 (Injection) (+)-Cis-2-(4-methoxyphenyl)-3-acetoxy-5-[2-(dimethylamino)ethyl]-8-chloro-2,3-dihydro-1,5-benzothiazepin-4(5H)-one maleate (10 g) was dissolved in 2 liters of distilled water for injection. The solution was filtered through a membrane filter with a pore size of 0.22 µm, and is poured into ampoules under sterilization conditions each in 2 ml and sealed to give ampoules for injection.

Claims: Use of (+)-cis-2-(4-methoxyphenyl)-3-acetoxy-5-[2-dimethylamino)ethyl]-8-chloro-2,3-dihydro-1,5-benzothiazepin-4-(5H)-one represented by the formula or a pharmaceutically acceptable salt thereof for preparing a prophylactic and curing composition for atherosclerosis, Mönkeberg's sclerosis or arteriosclerosis. Use according to claim 1 wherein the composition is in a dosage form for oral administration.

Inventors: IWASAKI, HITOSHI, KITAMURA, KAZUYUKI, OHTANI, AKIO
Applicants: TANABE SEIYAKU CO., LTD.
Application year: 1987
Main classification: A61K31
IPC codes: A61P9, A61K31, C07D281