SUNSCREENS FOR PROTECTION FROM SUN RADIATION

摘要

The present invention relates to sunscreen-doped sol-gel materials useful for protecting body tissues, such as skin, nails and hair and other surfaces from sunlight radiation. The sol-gel matrices are transparent to the UV radiation in the range above 250 nm and the doped sunscreen agents are either chemical or physical sunscreens capable of absorbing the UV radiation in the range above 250 nm. Any sunscreen molecule, moiety or particle may be used in the present invention. The sol-gel matrices may be particles in any shape, 0.01 - 100 microns in diameter, or they may be thin films, thin coatings or in the form of a monolith. The present invention also relates to a method for the preparation of sunscreen-doped sol-gel materials comprising condensation-polymerizing of at least one monomer selected from metal alkoxides, semi metal alkoxides, metal esters, semi metal esters and from monomers of the formula M(R)n(P)m, wherein M is a metallic or semi metallic element, R is a hydrolyzable substituent, n is an integer from 2 to 6, P is a non polymerizable substituent or a sunscreening moiety or derivative and m is an integer from 0 to 6, in the presence of at least one sunscreen ingredient, resulting in the entrapment of the sunscreen ingredients within the formed sol-gel matrix.