RP-HPLC method for simultaneous estimation of Rosuvastatin and Ezetimibe from their combination tablet dosage form

Rosuvastatin is an HMG Co-A inhibitor and Ezetimibe is an intestinal cholesterol absorption inhibitor. The combination formulation is used for the treatment of hypercholestrolemia. A simple, accurate and precise assay and rapid stability-indicating reversed-phase high performance liquid chromatographic (RP-HPLC) method has been developed and subsequently validated for the simultaneous estimation of Rosuvastatin (RSV) and Ezetimibe (EZE) from their combination drug product. The proposed method is based on the separation of the two drugs in reversed-phase mode using Water’s C18 250 × 4.6 mm, 5μ column maintained at an ambient temperature. The optimum mobile phase consisted of Acetonitrile: water: 0.02 M phosphate buffer pH 8 (40:10:50 v/v), flow rate of mobile phase was set 1.0 mL min−1 and PDA detection was performed at 230 nm. The method was validated according to ICH guidelines. It was found to be accurate and reproducible. Linearity was obtained in the concentration range of 30–90 μg mL−1 for both RSV and EZE with correlation coefficients of 0.999 and 0.998 respectively. Mean percent recovery of triplicate samples at each level for both drugs were found in the range of 98% to 100% with RSD of less than 2.0%. Rosuvastatin, Ezetimibe and their combination drug product were exposed to thermal, photolytic, hydrolytic and oxidative stress conditions and the stressed samples were analyzed by the proposed method. There were no interfering peaks from excipients, impurities or degradation products due to variable stress conditions and the proposed method is specific for the simultaneous estimation of RSV and EZE in the presence of their degradation products. The proposed method can be successfully applied in the quality control and stability samples of bulk manufacturing and pharmaceutical dosage forms.