HIGH SUNSCREEN EFFICIENCY WATER-IN-OIL EMULSION

摘要

The present invention relates to highly stable water-in-oil sunscreen emulsions that provide a high sunscreen efficiency ("SE") having a sun protection factor ("SPF") of X, where X is at least about 15, and having a sunscreen efficiency ("SE") of at least 2, preferably at least 3, where SE is the ratio of SPF over the total weight percentage of sunscreen actives based on the total weight of the composition. The emulsions of the present invention provide photoprotection for the period corresponding to the labeled SPF throughout the period of exposure to natural sunlight and comprises (i) at least one sunscreen active and (ii) an alkyl dimethicone copolyol emulsifier in which the water-soluble, alkyl-soluble and silicone-soluble groups of the dimethicone copolyol are in specific ratios to each other. Preferably, the high SE water-in-oil emulsion comprises both a UV-A sunscreen and UV-B sunscreen. More preferably, the combination of sunscreen actives is photostable.