Simplified HPLC method for simultaneous determination of erythromycin and tretinoin in topical gel form

Abstract

AbstractA simple, rapid and validated high‐performance liquid chromatographic method has been developed for the simultaneous determination of tretinoin and erythromycin in bulk and topical gel form. The analysis was achieved under isocratic mode with a specific reversed stationary phase and, using an eluent composed of acetonitrile/2‐methyl‐2‐propanol/hydrogen phosphate buffer of pH 7.0, delivered at a flow‐rate of 1.0 mL min−1, with UV detection at 215 nm. The procedure was validated for specificity, linearity, precision, accuracy and robustness. The calibration plots were linear over the concentration ranges of: 0.002–4.8 and 0.025–30 μg mL−1, with lower detection limits of 0.007 and 0.0008 μg mL−1 for erythromycin and tretinoin, respectively. The developed method was applied for the simultaneous quantitative determination of both drugs in their marketed alcoholic gel formulation. Results of the mean percentage recoveries were in the range of 99.5‐100.8%.