High-pressure liquid chromatographic determination of anthralin in ointments.

Anthralin concentration was determined in different ointments by high-pressure liquid chromatography, and results were compared with those of the USP assay technique. Significant differences existed between the claimed and the actual levels of anthralin in some preparations. Varying quantities of anthralin breakdown products were found, and their concentrations appear to be related to the nature of the formulation.