Development and validation of a method for simultaneous densitometric analysis of simvastatin and ezetimibe as the bulk drugs and in the tablet dosage form

Summary

Simvastatin is a selective HMG-CoA reductase inhibitor and ezetimibe has lipid-lowering activity. Both are potential anti-lipidemic agents used in combination to reduce the amount of cholesterol and triglycerides in systemic circulation. This paper describes a simple, precise, and accurate HPTLC method for simultaneous estimation of the compounds as the bulk drugs and in the tablet dosage form. Chromatographic separation was performed on aluminium-backed silica gel 60 F ₂₅₄ plates with 8:2 ( v/v) toluene-2-propanol as mobile phase. The separated spots were densitometrically evaluated at 240 nm. The drugs were satisfactorily resolved with R _F values 0.48 ± 0.01 and 0.53 ± 0.01 for simvastatin and ezetimibe, respectively. The accuracy and reliability of the method were assessed by determination of validation data for linearity (0.4–2.0 μg per spot for both simvastatin and ezetimibe), precision (intra-day RSD 0.51–1.04%, inter-day RSD 0.34–1.11% for simvastatin; intra-day RSD 0.47–0.61%, inter-day RSD 0.31–0.61% for ezetimibe), accuracy (98.50 ± 0.23 for simvastatin and 98.99 ± 0.38 for ezetimibe), and specificity, in accordance with ICH guidelines. The proposed method can be used for analysis of ten or more formulations on a single plate and is a rapid and cost-effective quality-control tool for routine simultaneous analysis of simvastatin and ezetimibe as the bulk drugs and in tablet formulations.