Use of diphenylethane derivatives for the manufacture of a medicament for the treatment of glaucoma

Abstract: The present invention provides a novel drug for treating glaucoma. The present invention relates to a therapeutic agent for glaucoma and an ocular hypotensive agent, which comprise an aminoalkoxybibenzyl represented by the formula (I): wherein R¹ represents a hydrogen atom, a C₁-C₅ alkoxy group, etc.; R² represents a hydrogen atom, a halogen atom, etc.; R³ represents a hydrogen atom, a hydroxyl group, -O-CO-(CH₂) l -COOH (wherein l is an integer of 1 to 3), etc.; and R⁴ represents -NR⁵R⁶ (wherein R⁵ and R⁶ independently represent a hydrogen atom or a C₁-C₈ alkyl group), etc. or a salt thereof as an active ingredient.

Description: FIELD OF THE INVENTION The present invention relates to a therapeutic agent for ophthalmic disease comprising aminoalkoxybibenzyls or a salt thereof as an active ingredient. More particularly, it relates to a therapeutic agent for glaucoma, and an ocular hypotensive agent. BACKGROUND OF THE INVENTION Glaucoma is considered to be a group of diseases wherein the entoptic tissue (particularly function of optic nerve cell) is damaged from lesions causing an abnormal ocular tension. Normally, the principal factors of the mechanism causing lesions are considered to be ischemic symptoms and disorder of optic nerve axonal flow due to mechanical compression in the lamina cribrosa caused by an increase in ocular tension. However, the mechanism of the increase in ocular tension is not clear at present. Further, in Japanese Patent Publication No. 13427/1988, the structure of aminoalkoxybibenzyls and a salt thereof is described. It is also described that they have an effect to increase an anticoagulant action and a prostaglandin I 2 action. The significance of glaucoma as degenerative disease has been increasing in advanced nations which have already entered in an ultra aging society, and good remedies for glaucoma have been requested still now. SUMMARY OF THE INVENTION In order to solve the above problems, the present inventors have studied intensively. As a result, it has been found that aminoalkoxybibenzyls having a specific structure or a salt thereof have an ocular tension reducing action and they are useful for treating glaucoma. The present invention provides of an aminoalkoxybibenzyl represented by the general formula (I): wherein R 1 represents a hydrogen atom, a halogen atom, a C 1 -C 5 alkoxy group or a C 2 -C 6 dialkylamino group; R 2 represents a hydrogen atom, a halogen atom or a C 1 -C 5 alkoxy group; R 3 represents a hydrogen atom, a hydroxyl group, -O-(CH 2 ) n -COOH (wherein n is an integer of 1 to 5) or -O-CO-(CH 2 ) l -COOH (wherein I is an integer of 1 to 3); R 4 represents a group of the general formula: wherein R 5 and R 6 independently represent a hydrogen atom or a C 1 -C 8 alkyl group, or a group of the general formula: wherein A is a C 3 -C 5 alkylene group which may be substituted with a carboxyl group; and m is an integer of 0 to 5, or a salt thereof, for the manufacture of a medicament for the treatment of glaucoma or ocular hypertension. DETAILED DESCRIPTION OF THE INVENTION The definition in the above formula will be explained in detail hereinafter. R 1 represents a hydrogen atom, a halogen atom (e.g. a chlorine atom, a fluorine atom), a C 1 -C 5 alkoxy group (e.g. a methoxy group, an ethoxy group, a butoxy group) or a C 2 -C 6 dialkylamino group (e.g. a dimethylamino group, a diethylamino group, a methylethylamino group); R 2 is a hydrogen atom, a halogen atom (e.g. a chlorine atom, a fluorine atom) or a C 1 -C 5 alkoxy group (e.g. a methoxy group, an ethoxy group, a butoxy group); R 3 represents a hydrogen atom, a hydroxyl group, -O-(CH 2 ) n -COOH (wherein n is an integer of 1 to 5) such as -O-(CH 2 ) 2 -COOH, -O-(CH 2 ) 3 -COOH, etc. or -O-CO-(CH 2 ) l -COOH (wherein l is an integer of 1 to 3) such as -O-CO-(CH 2 ) 2 -COOH, -O-CO-(CH 2 ) 3 -COOH; R 4 represents a group of the general formula: wherein R 5 and R 6 independently represent a hydrogen atom ; a C 1 -C 8 alkyl group such as a methyl group, a butyl group, hexyl group or a heptyl group ; an amino group, a methylamino group, an ethylamino group, a butylamino group, a hexylamino group, a heptylamino group, a dimethylamino group, a diethylamino group or a methylethylamino group; or a group of the general formula: wherein A represents a C 3 -C 5 alkylene group which may be substituted with a carboxyl group, such as and m is an integer of 0 to 5. In the present invention, the aminoalkoxy group of the formula: is preferably positioned on the 2-position in the aminoalkoxybibenzyl of the formula (I). Further, R 1 is preferably a hydrogen atom, a C 1 -C 5 alkoxy group or a C 2 -C 6 dialkylamino group. R 2 is preferably a hydrogen atom. R 4 is preferably a group of the formula: wherein at least one of R 5 and R 6 is a C 1 -C 8 alkyl group, or a group of the formula: wherein A is a methylene group. m is preferably an integer of 0 to 2. Further, pharmaceutically acceptable acid addition salts of the above compounds may also be included in the scope of the present invention. Examples of the acid addition salt include addition salts of acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, nitric acid, acetic acid, succinic acid, adipic acid, propionic acid, tartaric acid, maleic acid, oxalic acid, citric acid, benzoic acid, toluenesulfonic acid and methanesulfonic acid. Among aminoalkoxybibenzyls to be used in the present invention, examples of the most preferred compound include the following compounds: or its salts. The above aminoalkoxybibenzyls to be used in the present invention are known compounds and can be easily synthesized, for example, by the method described in Japanese Patent Publication No. 13427/1988. The therapeutic agents of the present invention may be oral agents, injections, eye drops and ointments. For oral agents, they may be tablets, capsules, powders, liquid preparations or elixirs. Non-toxic solids or liquids can be contained in the therapeutic agent as a pharmaceutically acceptable carrier. When the solid carrier is used, there is exemplified a conventional gelatin-type capsule. Further, an active ingredient can be used with or without auxiliaries to form a tablet or a powder packing. These capsules, tablets and powders contain normally 5 to 95 % by weight, preferably 25 to 90 % by weight, of the active ingredient. That is, these dosage forms can contain 5 to 500 mg, preferably 25 to 250 mg, of the active ingredient per dose. As the liquid carrier, there can be used water, oils originated from animals/vegetables (e.g. petroleum, peanut oil, soybean oil, mineral oil, sesame oil) or synthetic oils. As the liquid carrier, there can be suitably used saline, dextrose or similar sucrose solution and glycols (e.g. propylene glycol, polyethylene glycol). Particularly, an injection using saline contains normally 0.5 to 20 % by weight, preferably 1 to 10 % by weight, of the active ingredient. In case of the liquid preparation for oral administration, a suspension or syrup containing 0.5 to 10% by weight of the active ingredient is preferred. In this case, aqueous excipients (e.g. flavor, syrup, pharmaceutical micelle) may be used as the carrier. In order to prepare the eye drop, various additives described below may be appropriately added to a solution obtained by dissolving aminoalkoxybibenzyls represented by the formula (I) in water. As a buffer, for example, there can be used phosphate buffer, borate buffer, tartrate buffer, acetate buffer or an amino acid. As an isotonicity, for example, there can be used sugars (e.g. sorbitol, glucose, mannitol), polyhydric alcohols (e.g. glycerine, propylene glycol) and salts (e.g. sodium chloride). As an antiseptic, for example, there can be used quaternary ammonium salts (e.g. benzalkonium chloride, benzethonium chloride), paraoxybenzoates (e.g. methyl paraoxybenzoate, ethyl paraoxybenzoate), benzyl alcohol, phenethyl alcohol, sorbic acid and a salt thereof, thimerosal and chlorobutanol. As a viscous agent, for example, there can be used hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, hydroxypropylmethyl cellulose, carboxymethyl cellulose and a salt thereof. An ointment can be prepared by homogeneously mixing an aminoalkoxybibenzyl of the general formula (I) with a suitable base (e.g. vaseline) and optionally adding preservatives, stabilizers or other suitable additives. The dose of aminoalkoxybenzyls of the formula (I) contained in the preparations of the present invention varies depending upon the patient's age, weight and symptoms and the severity of the disease, and it should be finally decided by the clinical doctor. It is administered with a daily dose of normally 0.5 to 50 mg/kg, preferably 1 to 30 mg/kg, for one or more days. When the preparation of the present invention is the oral agent, 50 mg or 100 mg of the aminoalkoxybibenzyl are contained in the unit dosage form. For example, it is normally administered 1 to 3 times per day with a dose of 100 mg/time. In the case of the injection, the aminoalkoxybibenzyl is normally administered 1 to 4 times per day with a dose of 10 to 30 mg/time. In the case of the eye drop, an eye drop containing the amonoalkoxybibenzyl in a concentration of 0.1 to 1 % is prepared and the eye drop is administered 1 to 4 times per day. The preparations of the present invention can be widely applied in the ophthalmic field on the basis of an ocular hypotensive action of the aminoalkoxybibenzyls. For example, the preparations containing the aminoalkoxybibenzyls as the active ingredient of the present invention are useful for preventing or treating glaucoma, ocular hypertension and the like. Further, glaucoma include high tension glaucoma and low tension glaucoma (normal tension glaucoma) wherein glaucomatous abnormalities of optic disk and glaucomatous abnormalities of the visual field are recognized while exhibiting normal ocular tension. The preparations of the present invention are effective for both and are particularly effective for high tension glaucoma. The following examples further illustrate the present invention in detail. Example 1 To patients having an ocular tension of more than 21 mmHg, a preparation containing 100 mg of sarpogrelate hydrochloride (chemical name: (±)-1-[o-[2-(m-methoxyphenyl)ethyl]phenoxy]-3-(dimethylamino)-2-propyl hydrogensuccinate hydrochloride) was administered orally 3 times per day for 1 to 3 weeks to examine oral hypotensive action for the sarpogrelate hydrochloride. The results are shown in Table 1, below. In Table 1, the value of ocular tension immediately before administration of this preparation, the value after administration for a predetermined period and the value after a predetermined period have passed since the completion of the administration of this preparation are shown in the items of "before administration", "during administration" and "after completion of administration", respectively. Ocular tension (mmHg) No. Initial Sex Age Before administration During administration After completion of administration 1 S.H. F 70 Date 3/1 3/8 3/18 3/25 Right 26 21 21 22 Left 23 21 19 19 2 N.N. M 68 Date 2/15 2/22 3/22 4/5 Right 26 18 21 17 Left 18 16 15 15 3 T.K. M 50 Date 2/18 2/22 3/22 Right 20 15 20 Left 18 14 18 4 D.T. M 54 Date 2/14 2/28 3/28 Right 28 22 33 Left 27 22 25 5 R.A. F 23 Date 2/15 3/1 4/5 Right 28 24 23 Left 26 23 25 6 K.N. F 48 Date 2/22 3/1 3/11 3/25 Right 30 23 27 27 Left 30 22 25 24 7 T.M. M 51 Date 2/22 3/1 4/5 Right 23 19 18 Left 23 18 17 8 K.M. F 58 Date 2/22 3/1 4/5 Right 25 22 24 Left 23 22 21 9 Y.M. F 72 Date 2/22 3/1 3/22 Right 22 24 18 Left 16 18 19 10 S.T. F 68 Date 2/4 2/18 3/4 3/18 4/1 Right 28 25 26 28 27 Left 25 25 26 27 25 11 K.T. F 65 Date 2/22 3/1 3/15 4/5 Right 26 22 26 28 Left 26 22 22 28 12 M.N. F 65 Date 2/4 2/15 3/4 Right 24 17 21 Left 20 18 17 13 K.K. F 25 Date 2/22 3/1 3/22 Right 25 20 21 Left 15 13 14 14 H.N. M 69 Date 2/25 3/4 4/1 Right 23 22 24 Left 21 19 22 15 T.l. M 63 Date 3/1 3/8 3/15 3/29 Right 26 19 19 16 Left 26 19 19 16 16 T.S. F 62 Date 3/1 3/8 3/15 3/29 Right 24 21 21 20 Left 26 23 23 20 17 E.K. M 61 Date 2/18 2/25 Right 18 16 Left 28 23 18 K.T. F 45 Date 3/25 4/1 Right 26 23 Left 26 23 19 T.S. M 64 Date 3/10 3/17 Right 21 21 Left 16 13 20 R.O. M 78 Date 2/22 3/1 3/7 3/22 Right 28 28 28 25 Left 22 22 22 22 21 Z.I. M 59 Date 2/18 3/1 3/8 3/29 Right 38 16 16 13 Left 29 19 18 14 22 K.A. M 50 Date 2/9 2/15 Right 17 17 Left 29 44 23 M.E. M 64 Date 2/15 2/16 2/25 3/4 3/11 Right 17 17 16 19 20 Left 23 35 21 19 20 24 T.N. M 55 Date 3/15 3/22 Right 21 19 Left 21 19 25 T.T. M 70 Date 3/15 3/22 4/5 Right 24 17 16 Left 21 17 17 26 M.I. F 57 Date 3/15 3/22 4/5 Right 33 27 27 Left 32 27 26 27 H.I. M 56 Date 3/1 3/5 3/8 4/5 Right 21 23 19 21 Left 29 30 22 20 28 T.T. M 63 Date 3/11 3/14 3/18 3/25 Right 40 29 29 15 Left 19 17 16 14 Ocular tension was not changed in five cases (10, 14, 20, 23 and 24) and the ocular tension of the case 22 was increased. However, the ocular tension was decreased by 3 mm Hg or more in other cases. It can be judged from these data that sarpogrelate hydrochloride has an ocular hypotensive action. Further, the above data shows that the ocular hypotensive effect is maintained even if the administration of sarpogrelate chloride is stopped. Accordingly, sarpogrelate hydrochloride is useful as an ocular hypotensive agent. Furthermore, it is a good therapeutic means for glaucoma to decrease the ocular tension so that sarpogrelate hydrochloride is considered to be useful as a therapeutic agent for glaucoma, particularly glaucoma accompanied with an increase in ocular tension. Further, particularly significant side effects were not recognized in any of the cases.

Claims: Use of aminoalkoxybibenzyl compounds represented by formula (I) and/or their pharmaceutically acceptable salts: wherein R 1 represents a hydrogen atom, a halogen atom, a C 1 -C 5 alkoxy group or a C 2 -C 6 dialkylamino group; R 2 represents a hydrogen atom, a halogen atom or a C 1 -C 5 alkoxy group; R 3 represents a hydrogen atom, a hydroxyl group, -O-(CH 2 ) n -COOH (wherein n is an integer of 1 to 5) or -O-CO-(CH 2 ) l -COOH (wherein l is an integer of 1 to 3); R 4 represents a group of the general formula: wherein R 5 and R 6 independently represent a hydrogen atom or a C 1 -C 8 alkyl group, or a group of the general formula: wherein A represents a C 3 -C 5 alkylene group which may be substituted with a carboxyl group; and m is an integer of 0 to 5 for the manufacture of a medicament for the treatment of glaucoma or ocular hypertension. Use according to claim 1 whereby the compound represented by formula (I) is: Use according to claim 1 whereby the compound represented by formula (I) is: Use according to claims 1 to 3 for the manufacture of oral administration forms. Use according to claims 1 to 3 for the manufacture of injection solutions. Use according to claims 1 to 3 for the manufacture of eye drops. Use according to claims 1 to 3 for the manufacture of ointments.

Inventors: MANO TOMIYA, MANO, TOMIYA
Applicants: MITSUBISHI CHEM CORP, MITSUBISHI CHEMICAL CORPORATION
Application year: 1995
Main classification: A61K31
IPC codes: A61K9, A61K31, A61P27, C07D295