Delivery of hydroxy carboxylic acids

Abstract

The present invention provides greater than 99% pure bis(triorganosilyl)hydroxycarboxylates of the general formulae: R.sub.3 SiO--CHR.sup.1 --COO--SiR.sub.3 R.sub.3 SiO--CHR.sup.1 --R.sup.2 COO--SiR.sub.3 wherein each R is independently a monovalent straight or branched chain alkyl or alkenyl group having from 1 to about 6 carbon atoms, or an aryl group, R.sup.1 may be hydrogen, a monovalent straight or branched chain alkyl group having from 1 to about 18 carbon atoms, or an aryl group, and R.sup.2 is a divalent straight or branched chain alkyl group having from 1 to about 18 carbon atoms, an aryl group, or a straight or branched chain alkaryl group having from 7 to about 18 carbon atoms; a process for producing the bis(trimethylsilyl)hydroxycarboxylates comprising the trimethylsilylation with hexamethyldisilazane of the corresponding hydroxy carboxylic acids; cosmetic formulation comprising the greater than 99% pure bis(trimethylsilyl)hydroxycarboxylates dissolved in aprotic media; and a method of delivering hydroxycarboxylic acids to the epidermis without apparent irritation or inflammation of the epidermis or stratum corneum.

Dependencies are inferred from the claim text.