GB1107071A - Cosmetic depigmenting compositions - Google Patents

Abstract

Topical compositions for reducing the pigmentation of the skin comprise a cosmetically acceptable topical carrier together with 0.1-30% by weight of a C2-C6 aliphatic hydrocarbon substituted on one carbon by an -SH or -SCOR group, wherein R is alkyl having up to 6 carbons, and on a different carbon by an -NR\svR\yF group, wherein either (i) R\sv + R\yF together with the nitrogen form part of heterocycle; or (ii) R\sv is alkyl having up to 6 carbons and R\yF is H or an alkyl group having up to 6 carbons; or (iii) providing that the active agent is present only as the acid addition salt, or the composition has a pH below 6.0 and/or contains an anti-oxidant, R\sv and R\yF may each be H or an alkyl group having up to 6 carbons. The preferred depigmenting agents are 2-mercapto-ethylamine, and N,N-dimethyl-2-mercapto-ethylamine. The aliphatic residue may be saturated or unsaturated or cyclised (e.g. from ethane, n-butane or iso-butane, or the corresponding alkenes or cyclo-alkanes). The sulphydryl group is preferably on a primary carbon atom. When R\sv and R\yF form part of a heterocycle group, such groups may be morpholino, pyrrolidino or piperidino. The compositions may take the form of hydrophilic or hydrophobic ointments, creams, or aqueous, non-aqueous or emulsified lotions, and may include active ingredients such as exfoliating agents, and other depigmenting agents (e.g. catechol). The preferred pH is 3.9 to 4.1; preferred anti-oxidants are the methyl or propyl esters of p-hydroxy-benzoic acid. The acid addition salt of the active agent may be the hydrochloride.