Patent GB-1263189-A (GB)
Title: Compositions and method for colouring the skin
Inventor: KALOPISSIS G
IPC: A61K8/49
Filed: 1969-03-14
Abstract: 1,263,189. Colouring skin. L'OREAL. 14 March, 1969 [14 March, 1968], No. 13689/69. Addition to 1,228,634. Heading A5B. Artificial tanning compositions for colouring the skin comprise (a) at least one tetrazolium compound of the formula: in which each of R and R", which may be the same or different, represent a substituted or unsubstituted aromatic radical, R being divalent, R' represents a hydrogen or halogen atom, an alkyl, thiol, heterocyclic, or a substituted or unsubstituted aromatic radical, or a group of the formula -N=N-Ar in which Ar represents a substituted or unsubstituted aromatic radical, n is 1 or 2, Y represents a hydrogen atom when n is 1, and a radical of the formula: in which R, R' and R" are as defined above, when n is 2; and A- represents an anion, and (b) a reducing agent which is either a reducing enzyme or a hydroxylated benzene, naphthalene or indole dyestuff. Preferably A- represents a halide, methyl sulphate, sulphate or acetate ion; each of the aromatic radicals is a phenyl radical or a nitro-, methoxy- or halo-substituted aromatic radical; R is p-nitrophenyl, o-methoxyphenyl, o-methoxy-p-phenylene or p-phenylene and R' is p-methoxyphenyl. Preferred tetrazolium compounds include 3-p'-nitrophenyl-2, 5-diphenyltetrazolium chloride; 3, 3'-p", p"'-[(o", o'"-dimethoxy) biphenyl]-2, 2', 5, 5'-tetraphenylditetrazolium chloride; 3-o'-methoxyphenyl-2, 5-diphenyltetrazolium chloride; 3, 3'-p", p"'-[(o", o"'-dimethoxy) biphenyl]-2, 2'-diphenyl-5, 5'-dianisyl-ditetrazolium chloride, 3, 3-p", p"'-diphenylene-2, 2', 5, 5'-tetraphenylditetrazolium chloride and 2, 3, 5-triphenyltetrazolium chloride. The composition may contain 0.1 to 2% by weight of the tetrazolium compound, have a pH from 3 to 8, and be in the form of an alcoholic solution, cream, gel or aerosol additionally containing a conventional cosmetics adjuvant, a surface-active agent and/or a perfume. The reducing enzyme may be riboflavin decarboxylase, or a metalloporphyrin, the dyestuff may be 1, 2, 4-trihydroxybenzene, 2, 3, 5- trihydroxytoluene, 1, 2, 4-trihydroxynaphthalene or 5, 6-dihydroxyindole and the molar ratio of tetrazolium compound to reducing agent is from 0.1:1 to 10:1. A two-component pack comprises, as the first component, at least one tetrazolium compound as above defined and, as the second component, a reducing agent which is (i) sodium ascorbate, sodium borohydride, sodium hydrogensulphite or a thiol, (ii) a colourless compound which is capable of being oxidised to a coloured compound or (iii) a reducing enzyme or a hydroxylated benzene, naphthalene or indole dye. The reducing agent may be aminohydroquinone hydrobromide, a leuco derivative or an oxidation dyestuff. Skin is coloured by application thereto of a composition comprising at least one of the above-defined tetrazolium compounds and preferably the composition also contains, or there is also applied to the skin, a reducing agent which does not attack the skin and which has an oxidation-reduction potential less than that of the tetrazolium salt-formazan system. The composition containing the tetrazolium compound may be first applied to an area of the skin and when the skin is dry a composition containing at least one reducing agent is applied to the same area.