Aqueous nano-particulate dispersion comprising a UV absorber/polymer mixture for pharmaceutical /cosmetic applications

摘要

Use of a concentrated aqueous polymer dispersion with an average particle size of less than 1000 nm comprising;

(a) a polymer carrier prepared by heterophase radical polymerization of at least one ethylenically unsaturated monomer in the presence of

(b) an oil-soluble organic UV absorber selected from the class of p-aminobenzoic acid derivatives; salicylic acid derivatives; benzophenone derivatives; diphenyl acrylate derivatives; benzofuran derivatives; polymeric UV absorbers, comprising one or more organosilicon radicals; cinnamic acid derivatives; camphor derivatives; s-triazine derivatives; trianilino-s-triazine derivatives; menthyl anthranilates; and benzotriazole derivatives as defined herein; characterized in that the weight ratio of the oil-soluble organic UV absorber (b) to polymer carrier (a) is greater than 50 parts UV absorber per 100 parts of carrier, for the protection of human and animal hair and skin against the damaging effect of UV radiation. A cosmetic composition comprising the aforementioned aqueous polymer dispersion is also described that comprises a cosmetically suitable carrier. The concentrated aqueous polymer dispersions show unexpectedly high sunscreen effects and a positive skin feeling.