RP-HPLC Method for Simultaneous Estimation of Simvastatin and Ezetimibe in Bulk Drug and its Combined Dosage Form

This work is concerned with application of simple, accurate, precise and highly selective reverse phase high performance liquid chromatographic (RP-HPLC) method for simultaneous estimation of simvastatin and ezetimibe in combined dosage form. Chromatographic separation was achieved isocratically at 25°C±0.5°C on Luna C₁₈ column (250×4.6 mm i.d.) with a mobile phase composed of methanol: water: acetonitrile in the ratio of 75: 18.75: 6.25 % v/v/v at flow rate of 1.8 ml/min. Detection is carried out using a UV-PDA detector at 231 nm. The retention time of simvastatin and ezetimibe was found to be 13.5±0.5 min and 4.02±0.3 min. respectively. The method was found to be linear in the range of 1-50 μg/ml with mean recovery of 99.21% for simvastatin and 99.50% for ezetimibe. The correlation coefficients for all components are close to 1. The developed method was validated according to ICH guidelines and values of accuracy, precision and other statistical analysis were found to be in good accordance with the prescribed values. Thus the proposed method was successfully applied for simultaneous determination of simvastatin and ezetimibe in routine analysis.