Chemical stabilization of solubilized retinoids and aqueous compositions comprised thereof
Solubilized retinoids within cosmetic/pharmaceutical compositions, e.g., aqueous gels or oil-in-water emulsions, are chemically stabilized by introducing therein an amount of at least one base effective to salify such retinoids; the resultant compositions are useful in cosmetics and dermatology, e.g., for treating acne vulgaris or psoriasis.
1 . A topically applicable, physically/chemically stable cosmetic/pharmaceutical composition which comprises an aqueous phase and an active phase, said aqueous phase comprising water and said active phase comprising at least one solubilized retinoid, an amount of at least one base effective to salify said at least one retinoid and a hydrophilic cosolvent.
2 . The cosmetic/pharmaceutical composition as defined by claim 1 , formulated as an aqueous gel.
3 . The cosmetic/pharmaceutical composition as defined by claim 1 , formulated as an oil-in-water emulsion.
4 . The cosmetic/pharmaceutical composition as defined by claim 1 , comprising a retinoid having the formula (Ia):
5 . The cosmetic/pharmaceutical composition as defined by claim 1 , said at least one base comprising a mineral and/or organic base and/or a basic amino acid.
6 . The cosmetic/pharmaceutical composition as defined by claim 1 , said at least one base comprising sodium hydroxide.
7 . The cosmetic/pharmaceutical composition as defined by claim 1 , comprising from 1 to 10 molar equivalents of said at least one base, based on said at least one retinoid.
8 . The cosmetic/pharmaceutical composition as defined by claim 1 , comprising from 0.01% to 5% by weight of said at least one retinoid.
9 . The cosmetic/pharmaceutical composition as defined by claim 1 , comprising from 40% to 80% by weight of water and from 5% to 20% by weight of a glycol cosolvent.
10 . The cosmetic/pharmaceutical composition as defined by claim 1 , comprising:
a) 0.1% of S-(+)-2-hydroxy-4-[3-hydroxy-3-(5,6,7,8-tetrahydro-5,5,8,8-tetramethylnaphthalen-2-yl)-1-propynyl]benzoic acid;
b) 2 molar equivalents of sodium hydroxide for salifying the retinoid;
c) 0.5% of Carbopol 980;
d) 65% to 75% of water; and
e) 15% of propylene glycol.
11 . The cosmetic/pharmaceutical composition as defined by claim 1 , comprising from 0.05% to 15% by weight of at least one gelling agent.
12 . The cosmetic/pharmaceutical composition as defined by claim 1 , comprising up to 15% by weight of at least one emulsifying agent.
13 . A process for chemically stabilizing at least one solubilized retinoid within a cosmetic/pharmaceutical composition which comprises said at least one retinoid, a principal solvent and a cosolvent, comprising introducing therein an amount of at least one base effective to salify said at least one retinoid.
14 . The process as defined by claim 13 , said principal solvent comprising water.
15 . The process as defined by claim 14 , said at least one retinoid having the formula (Ia):
16 . The process as defined by claim 14 , said cosmetic/pharmaceutical composition comprising an aqueous gel.
17 . The process as defined by claim 14 , said cosmetic/pharmaceutical composition comprising an oil-in-water emulsion.
18 . A regime or regimen for the prevention or treatment of a dermatological affliction or condition associated with cell differentiation and/or proliferation disorders and/or keratinization disorders, comprising topically applying onto the skin, integuments and/or mucosae of an individual in need of such treatment, a thus effective amount of the cosmetic/pharmaceutical composition as defined by claim 1 .
19 . A regime or regimen for the prevention or treatment of acne vulgaris or psoriasis, comprising topically applying onto the affected skin area of an individual in need of such treatment, a thus effective amount of the cosmetic/pharmaceutical composition as defined by claim 1 .
20 . A regime or regimen for treating skin prone to acne, for causing hair regrowth or preventing hair loss, for combating the greasy appearance of the skin or hair, in providing protection from the harmful effects of the sun, in treating physiologically dry skin or for preventing and/or combating photoinduced or chronological aging, comprising topically applying onto the affected skin/hair of an individual in need of such treatment, a thus effective amount of the cosmetic/pharmaceutical composition as defined by claim 1.