Development of a Reproducible, Sensitive and Rapid Reversed Phase Chromatographic Method for the Estimation of Isotretinoin Incorporated in Bulk Drugs, Pharmaceutical Dosage Forms and Biological Matrix

The current study entails the development and validation of a high-performance liquid chromatographic method for quantitative estimation of isotretinoin present in bulk, pharmaceutical dosage forms as well as in human plasma and skin as biological matrix. The method employed reversed phase chromatography employing an RP-C18 column with an isocratic mobile phase consisting of acetonitrile, methanol and water (50:45:5 v/v) set at a flow rate of 0.8 ml/min. The analyte detection was done by ultraviolet detection (UV) at 355 nm. The pH of the mobile phase was adjusted to 4.5 ± 0.01 using acetic acid. The isotretinoin was extracted from plasma by liquid-liquid extraction method. A sharp peak with peak asymmetry value of 1.16 was observed for isotretinoin at a retention time of 5.2 ± 0.01 min. The regression equation was linear over concentration range between 0.1-100 μg/ml and regression co-efficient was found to be 0.999 with good accuracy and precision. The limit of detection (LOD) and quantification (LOQ) were found to be 0.006 and 0.018 μg/ml, respectively. The wide range of linearity, accuracy, short retention time and isocratic elution imply that the method is suitable for routine estimation of isotretinoin in bulk, pharmaceutical dosage forms and human plasma with good accuracy and precision.