L’Oréal Awarded Patent For Photoprotective Cosmetic

US Patent No. 9,381,383 B2; L’Oréal has patented a photoprotective cosmetic composition including particles having a polymeric multilayer interference structure, at least two layers comprising an amphiphilic polymer, wherein the particles have a swelling agent including at least one optically active material, at least one optically active material being dissolved in the swelling agent and being included within the amphiphilic polymer, wherein the amphiphilic polymer comprises a diblock copolymer with the form A-B where A is polystyrene and B is poly(2-vinyl pyridine), wherein the blocks of the diblock copolymer have the same number average molecular weight, wherein the diblock copolymer has a periodic structure having two separate blocks of A-B alternated at regular intervals, and wherein each block of the diblock copolymer has a number average molecular weight of from 1,000 g/mol to 500,000 g/mol, and wherein the particles having a polymeric multilayer interference structure including a fixing agent selected from inorganic materials, glycols, and PEGs having a number average molecular weight in a range of from 400 g/mol to 50,000 g/mol.