Development and Validation of RP-LC Method for the Simultaneous Determination of Simvastatin and Ezetimibe in Fixed-Dose Combination Tablets and in Rabbit Serum

Combined drug therapy which is based on the co-administration of two or more drugs, have been used for a long time, to treat diseases. In this study, a simple, selective and rapid RP-LC method has been developed and validated for the sensitive and simultaneous determination of simvastatin (SMV) and ezetimibe (EZE) in fixed-dose combination tablets and in rabbit serum using a simple sample preparation procedure. The developed RPLC method for these lipid-lowering agents was completely validated and in the linear range of 0.05–50 µg mL− 1 EZE and 0.05–10 µg mL− 1 SMV. The calibration curves were obtained with limit of detection values of 0.013 µg mL− 1, 0.009 µg mL− 1—for EZE and SMV, respectively. The developed method was successfully applied to the analysis of EZE and SMV in fixed-dose combination tablets and in rabbit serum, and no interference was observed from any excipients and endogenous substances in the rabbit serum samples. Dissolution profiles of the pharmaceutical dosage form of these lipid-lowering agents were also studied.