Drug – bio-affecting and body treating compositions – Bleach for live hair or skin
Patent
1992-10-13
1996-06-18
Page, Thurman K.
Drug, bio-affecting and body treating compositions
Bleach for live hair or skin
514166, 514551, A61K 748, A61K 700
Patent
active
055275230
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to amino acid esters of hydroquinone, to the pharmaceutical or cosmetic compositions in which they are present, in particular the dermatological compositions with depigmenting activity, and to their pharmaceutical, cosmetic or aesthetic applications.
The present invention further relates to the preparation of these novel hydroquinone esters from natural amino acid derivatives.
Hydroquinone and its simple derivatives such as the monomethyl ether and the monobenzyl ether, although currently considered to be among the least irritant of the tyrosinase inhibitors and having an optimal efficacy/tolerance ratio, are nevertheless known to cause irritation and significant sensitization of the skin which is incompatible with prolonged use as a depigmenting agent, either in dermatology or in cosmetology.
In fact, it is imperative for topical depigmenting agents to satisfy three rules: they should have a depigmenting effect only on the lesions to be treated, they should produce neither irritation nor post-inflammatory secondary pigmentation and they should cause neither allergy nor a systemic depigmenting effect.
Some synthetic corticoid or mercury products are active on melanogenesis but have a number of side effects which contraindicate repeated local use.
In order to limit the skin irritation, a number of combinations have been proposed. The combination hydroquinone--vitamin A acid and a corticoid may be mentioned in particular, which has been limited in practice because of the existence of other side effects [J. Invest. Dermatol. 73(5), p. 357, (1979)].
Furthermore, hydroquinone and its simple derivatives have the major disadvantage of being sensitive to oxidation, even in the presence of stabilizers such as ascorbic acid or sodium sulphide [J. Invest. Dermatol. 62, p. 436, (1974)], which results on the one hand in the darkening of the preparations and on the other hand in the generation of entities which are particularly irritant towards the skin, thereby limiting the topical application of hydroquinone and its simple derivatives mentioned above.
To mitigate these different disadvantages, other hydroquinone derivatives have been proposed. French patent no 2 577 805 in the name of SHISEIDO and European patent application no 60092 in the name of SUNSTAR KABUSHIKI KAISHA respectively claim heterosides and C.sub.1 to C.sub.20 carboxylic acid esters of hydroquinone.
However, the products described in both French patent no 2 577 805 and the European patent application have a number of disadvantages; in fact, the products described in French patent no 2 577 805 have an exclusively hydrophilic character which does not allow penetration to the deep layers of the skin where the action of the active principle can be prolonged, and which thus limits the efficacy of these products; as regards the products described in European patent application no 60092, they have an essentially lipophilic character which also limits the efficacy of these products to the extent that their diffusion in contact with the biological fluids is weak.
The object of the present invention was consequently to provide hydroquinone derivatives which meet the practical needs better than the derivatives of the prior art, especially in that they have a remarkable stability to light, heat and water.
The present invention relates to natural amino acid esters of hydroquinone which can have an amphiphilic character, and to the formulations or compositions in which they are present.
These products have the following general formula (I): ##STR2## in which: A is hydrogen, benzyl, an alkyl containing 1 to 4 carbon atoms which is unsubstituted or substituted by one of the following groups: OH, SH, C.sub.6 H.sub.5 --OH, CO--NH.sub.2, COOH, NH.sub.2, NH--CNH.sub.2 --NH.sub.2, C.sub.6 H.sub.5, indole, S--CH.sub.3, or imidazole, which substituents may themselves be esterified; A corresponds to the radical of a natural alpha-amino acid or a simple derivative thereof, such as a methyl or ethyl ester or a primary amide in the case of dicarbox
REFERENCES:
patent: 4466955 (1984-04-01), Calvo
patent: 4518789 (1985-05-01), Yu
patent: 4526779 (1985-07-01), Hashimoto
patent: 4764505 (1988-08-01), Fujinuma
patent: 4876084 (1989-10-01), Hori
patent: 5001156 (1991-03-01), Phillipe
patent: 5063056 (1991-11-01), Yamamoto
J. S. Bradshaw et al., "Polysiloxanes Containing Thermally Stable Chiral Amide Side-Chains for Capillary Gas ad Supercritical Fluid Chromatography", Journal of Chromatography, vol. 405, 18 Sep. 1987, pp. 169-177.
M. S. Matta et al., "Acylation of Subtilisin Carlsberg by Phenyl Esters", Chemical Abstracts, vol. 84, No. 17, 26 Apr. 1976, p. 203.
Derrieu Guy
Laruelle Claude
Raynier Bernard
Gardner Sally
Page Thurman K.
Virbac S.A.
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