Determination of tretinoin in creams by high-performance liquid chromatography.

A stability indicating reversed-phase high-performance liquid chromatographic method has been developed to quantify tretinoin (all-trans-retinoic acid) in cream formulations. Tretinoin cream samples were dissolved directly in tetrahydrofuran and diluted for injection. Separation was accomplished on a 15 cm Nova-Pak C18 column using a tetrahydrofuran-phosphate buffer solvent system (42:58, v/v) and 1.0 ml/min flow-rate. The method is able to separate tretinoin from its degradation products formed under stressing conditions. Excellent precision and accuracy were found for the assay of tretinoin in the cream formulations.