Patent ID: 6375936
Filing Date: 2002-04-23
Classification: A61K,A61Q,B82Y,Y10S

Abstract:
A cosmetic composition for topical use in the form of a dispersion comprising two immiscible phases stabilized with at least one anionic surfactant selected from the group consisting of a salt of a fatty acid, with a monovalent or polyvalent metal, an ammonium base or an organic base; and a hydrophilic ultraviolet radiation screening agent comprising at least one partially or totally neutralized sulphonic acid function, which can be adsorbed at the interface of the said immiscible phases, having the formula: in which:Z denotes a group of formula: wherein R2 is â€”H or â€”SO3H; n is 0 or an integer greater than or equal to 1 and less than or equal to 4; R1 represents one or more identical or different, linear or branched alkyl or alkoxy radicals containing from 1 to 4 carbon atoms, the two methylidenecamphor radicals on the phenyl ring being in a meta or para position relative to each other, said composition further comprising a metal oxide nanopigment selected from the group consisting of a titanium oxide nanopigment, a zinc oxide nanopigment, an iron oxide nanopigment, a zirconium oxide nanopigment, a cerium oxide nanopigment, and mixtures thereof, said nanopigment being coated with a hydrophobic hydrocarbon-based coating agent and having an average primary particle size ranging from 5 to 100 nm, the composition further comprising a cationic or zwitterionic amphiphilic compound which leads, with the anionic surfactant, to the formation of a compound capable of lowering the water/liquid paraffin interface tension at 40Â° C. by more than 14 mN.mâˆ’1 for an anionic surfactant concentration of 0.1 mmol/100 g, by more than 26 mN.mâˆ’1 for an anionic surfactant concentration of 0.5 mmol/100 g and by more than 33 mN.mâˆ’1 for an anionic surfactant concentration of 1 mmol/100 g.