Androgenic alopecia is the most frequent form of hair loss, which can occur both in men and in women. The term “androgenic alopecia” is understood as meaning hair deficiency states the cause of which is a genetically determined hypersensitivity of the hair root to 5α-dihydrotestosterone.
A typical example of androgenic alopecia is the common baldness in men, that is, male pattern baldness. However, androgenic alopecia can also occur in women of sexually mature age-with or without the clinical features of male baldness.
A prerequisite of treatment of androgenic hair loss is early interruption of the pathogenetic processes which cause degeneration of the hair follicle. To achieve a normalization of the hair cycle, that is, prolonging of the growth phase of the hair, it is necessary to reduce the biologically active amount of androgen at the follicle. When endocrinopathies have been ruled out and medicaments which comprise testosterone or other substances having an androgenic action have been discontinued, inhibition of androgen stimulation at the target organ is necessary. To achieve this aim, two routes are theoretically conceivable: firstly, inhibition of the activity of the 5α-reductase and therefore a reduction in the conversion of testosterone into 5α-dihydrotestosterone, for example by estrogen, and secondly, blocking of the dihydrotestosterone-sensitive receptor protein, for example by antiandrogens.
Since all systemic treatment measures for androgenic alopecia are directed against the androgen action, they can be used on women of child-bearing age only with simultaneous contraception. After introduction of oral contraceptives, it was found that the course of androgenic alopecia and its concomitant symptoms is influenced favorably or unfavorably depending on whether an estrogen-emphasized preparation or a preparation with a residual androgenic action is administered.
In the absence of another risk-free alternative with a more potent action, estrogen-containing hair lotions have hitherto been described for treatment of androgenic alopecia in men. In women, this local treatment is recommended as an assisting measure, and the main emphasis is placed on systemic treatment.
All patients are instructed to treat the region of the scalp still covered with hair and not the areas which are already bald. In many cases, it is possible to alleviate or to stop the episodes of hair loss with the aid of these local measures.
Antiandrogens having a topical action are known from French Patent 2,693,461 and U.S. Pat. No. 5,411,981 (443-(4-hydroxybutyl)-4,4-dimethyl-2,5-dioxo-1-imidazolidinyl]-2-(trifluoromethyl)benzonitriles) and from PCT Application WO 98/05654 (3-aryl-2,4-dioxo-oxazolidines), but are currently not yet generally commercially available for treatment purposes.
Both classes of substance show a high bonding affinity for the androgen receptor at the hair root after topical application, with virtually no systemic activity.
Due to the teratogenicity of antiandrogens, intrinsic to the substances, with an influence on sex differentiation in the late stage of pregnancy, the substances mentioned cannot be used in the form of conventional aqueous/alcoholic hair lotions because of the occurrence of precipitates of the substances at the application site after evaporation of the solvent and the associated toxicological risk of transfer of the substance to pregnant women. Furthermore, delayed release of the active compounds over a relatively long period of time, in order to avoid high systemic concentrations of the active substance and the associated occurrence of systemic antiandrogenic effects, is not guaranteed by conventional formulations for application to the scalp.
In order to make the antiandrogenic active compounds in the above-mentioned references available for a reliable and effective treatment, it was therefore necessary to discover compositions which do not have the disadvantages described for conventional scalp treatment compositions.
The object is achieved by the compositions according to the invention, comprising one or more topical antiandrogens according to U.S. Pat. No. 5,411,981 or WO 98/05654, the disclosures of both of which are explicitly incorporated herein by reference, a physiologically tolerated volatile solvent or solvent mixture, a plasticizer and one or more physiologically acceptable film-forming agents which, after drying of the composition, form flexible films which adhere to the scalp and are capable of releasing the active compounds employed in a controlled manner and over a certain period of time. Moreover, the undesirable precipitation of the active compound at the application site is prevented by the compositions according to the invention.
The invention therefore relates to a composition comprising at least one physiologically tolerated film-forming agent, at least one physiologically tolerated solvent, at least one plasticizer and a compound of the formula I
or a stereoisomeric form or a physiologically tolerated salt of any of the foregoing, in which:
R1 is 1) —CN,
3) a halogen, or
R2 is 1) —CF3,
2) a halogen, or
R3 is 1) ═O,
2) ═S, or
X is 1) a radical of formula II
2) a radical of formula III
or X and Y together form a group of formula IV
in which R4 is 1) hydrogen atom,
3) (C2-C6)-alkenyl-, or
wherein the alkyl is mono- to trisubstituted by
4.4 —CN, or
Y is 1) a radical of formula V