Quantitative determination of benzoic acid and salicyclic acid in ointments by high-pressure liquid chromatography.

Benzoic acid and salicyclic acid in ointments were analyzed quantitatively by reversed-phase high-pressure liquid chromatography. Both benzoic and salicyclic acids can be assayed in combinations directily without interference from each other or the ointment bases. The method is accurate, simple, and rapid. Excellent results were obtained with three commercial bases.