QUANTITATIVE HPTLC DETERMINATION OF BENZOYL PEROXIDE IN ACNE MEDICATIONS

A method has been developed for determination of the active ingredient benzoyl peroxide in topical pharmaceutical preparations used for cont rol of acne. The method involves separation of benzoyl peroxide on a p readsorbent HPTLC silica gel plate containing fluorescent phosphor, de tection by fluorescence quenching, and quantification by densitometric scanning. Benzoyl peroxide was detected and quantified with a sensiti vity limit of 50 ng, and no interference was encountered from other in gredients in the formulations. The method was applied to the analysis of four different types of commercial medications having label values of 5 or 10% hydrogen peroxide. A gel skin medication not containing be nzoyl peroxide was spiked with 5% benzoyl peroxide to validate accurac y, and recovery was 101%. All analyses were performed with three or fo ur replicates to evaluate precision; coefficients of variation average d 2.3%.