DETERMINATION BY HPLC OF KETOPROFEN IN AQUEOUS MEDIUM USED FOR IN VITRO SKIN PERMEATION STUDIES

A HPLC procedure with UV detection has been developed for quantification of ketoprofen release into receptor solution used as acceptor phase for in vitro skin permeation studies. The assay involves an extraction of the drug and the internal standard into chloroform from acidified aqueous media and assay by a reverse phase C18 column. Chromatographic separation was achieved using a mobile phase containing a mixture of acetonitrile and phosphate buffer, pH 3.0, pumped at flow rate of 0.8 ml/min. The chromatograms were completely free from interfering peaks; relative retention times of internal standard and ketoprofen were ? 4.12 and ? 7.01 min, respectively. Calibration curves showed good linearity over the concentration range (100.0–1000.0 ng/ml) examined. Drug recovery was 97.18% and inter- and intra-assay variation coefficients were less than 6%.