SYNTHESIS OF FATTY ALCOHOL ESTERS OF .ALPHA.-HYDROXY CARBOXYLIC ACIDS AND THEIR USE AS PERCUTANEOUS ABSORPTION ENHANCERS

摘要

The present invention provides a novel approach for the preparation of fattyalcoholesters of a-hydroxy carboxylic acids. in one form of the invention, the targetfatty alcoholester of a-hydroxy carboxylic acid is produced by converting a lower alkylester of .alpha.-hydroxycarboxylic acid into a fatty alcohol ester of .alpha.-hydroxy carboxylic acidviaalcoholysis (i.e., transesterification). The transesterification process is anequilibriumreaction, catalyzed chemically (i.e., with acids or bases) or enzymatically,that is shiftedin the desired direction to produce the desired product, One preferred way ofshifting thereaction in the direction of the desired product is by reducing theconcentration of one ofthe products (e,g., distillation of a lower-boiling alcohol as soon as it isformed). Anotherpreferred way of shifting the reaction in the direction of the desired productis byincreasing the concentration of one of the reactants (e.g., adding more of thestartingester).