Title:  Minoxidil compositions for external use

United States Patent:  6,265,412

Assignee:  Taisho Pharmaceutical Co., Ltd. (JP)

Filed:  November 20, 2000

PCT NO:  PCT/JP99/02722

102(e) Date:  November 20, 2000

PCT PUB. Date:  December 2, 1999

Foreign Application Priority Data:  May 26, 1998[JP] (10-144598)

There is provided a composition for external use with a reduced skin irritation comprising minoxidil and 0.01 to 2 parts by weight of at least one antihistaminic agent selected from the group consisting of chlorphenylamine maleate, diphenylimidazole, diphenhydramine and a salt thereof per 1 part by weight of minoxidil.

DISCLOSURE OF THE INVENTION

As a result of extensive researches in order to overcome the above problem, the present inventors have found that the skin irritation as a side-effect of the minoxidil-containing composition for external use is surprisingly reduced by combining the minoxidil-containing composition for external use with an antihistaminic agent which has been used as a medicine to relieve itching, thereby the present invention has been accomplished. That is, the present invention is directed to a composition for external use comprising minoxidil and an antihistaminic agent.

Preferably, the composition for external use according to the present invention contains minoxidil in an amount of from 0.1 to 5% by weight,. and an antihistaminic agent in an amount of from 0.01 to 5% by weight. When the amount of minoxidil is less than 0.1% by weight, the therapeutic effect may not be expected, and when it exceeds 5% by weight, there may be a risk that a lowering action of blood pressure occurs. Furthermore, when the amount of the antihistaminic agent is less than 0.01% by weight, the inhibition effect of skin irritation may be weak, on the contrary, when it exceeds 5% by weight, there may be a possibility that the antihistaminic agent causes skin irritation by itself. With regard to the amount ratio of minoxidil and the antihistaminic agent, it is preferable that the amount of the antihistaminic agent ranges from 0.01 to 2 parts by weight per 1 part by weight of minoxidil.

Preferred examples of the antihistaminic agent in the present invention are chlorphenylamine maleate, diphenylimidazole, diphenhydramine and a salt thereof. The amount of the antihistaminic agent to be incorproated ranges preferably from 0.01 to 1 part by weight for chlorphenylamine maleate or diphenylimidazole and from 0.02 to 2 parts by weight for diphenhydramine or a salt thereof, respectively, per 1 part by weight of minoxidil. These antihistaminic agents may be also properly used in combination.

In order to further reduce the skin irritation of the composition for external use of the present invention, it is preferable to further incorporate an anti-inflammatory agent thereinto. Suitable anti-inflammatory agent includes glycyrrhetic acid, glycyrrhizic acid, a salt thereof, dimethylisopropylazulene and sodium azulenesulfonate. The amount of the anti-inflammatory agent is not particularly limited unless the effect of the present invention is degraded thereby, but preferably it is in the range of from 0.05 to 1% by weight.

The composition for external use according to the present invention can contain effective components other than the above-mentioned effective components. Specific examples thereof include carpronium chloride, benzyl nicotinate, tocopherol acetate, urea, salicylic acid, sodium hyaluronate, chondroitin sulfuric acid, crude drugs (e.g., swertia, panax ginseng, capsicum, plant worm vegetative wags, saffron or extracts thereof), antimicrobial agents (e.g., chlorhexidine gluconate, isopropyl methyl phenol, quaternary ammonium salts or hinokitiol).

The composition for external use of the present invention, if necessary, can contain components which are ordinarily used for making preparations for external use in a desired form such as liquids, creams, ointments, gels or aerosols; and specific examples of such components are water, lower alcohols, solubilizers (e.g., fatty acid esters, polyhydric alcohols, polyhydric alcohol fatty acid esters, medium chain fatty acid glycerides, vegetable oils, animal oils, alkyl glycerol ethers and hydrocarbons), surface active agents (e.g., nonionic surface active agents, lecithin derivatives and high molecular emulsifiers), emulsifying stabilizers, gelling agents, adhesives, anti-oxidants (e.g., dibutylhydroxytoluene and isopropyl gallate), refrigerants (e.g., menthol, mentha oil and camphor), perfumes or dyes.

Claim 1 of 1 Claim

What is claimed is:

1. A composition for external use consists essentially of 1 part by weight of minoxidil and 0.01 to 2 parts by weight of at least one antihistaminic agent selected from the group consisting of chlorphenylamine maleate, diphenylimidazole, diphenhydramine and a salt thereof.

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