Development and Validation of a Stability-indicating Micellar Electrokinetic Chromatography Method for the Determination of Ezetimibe in Pharmaceutical Formulations

A micellar electrokinetic chromatography (MEKC) method was validated for the analysis of ezetimibe. The method was carried out on a fused-silica capillary (50 pm i.d.; effective length, 40 cm). The background electrolyte consisted of a 25 mM borate buffer and 25 mM anionic detergent SDS (pH 9.75)/methanol (90:10, v/v). The capillary temperature was maintained at 35°C, the applied voltage was 30 kV; the injection was performed using a pressure mode at 50 mbar for 5 s, with detection at 232 nm. The method was linear in the range of 2–150 pg/mL (R2 = 0.9999). The specificity and the stability-indicating capability were proven through degradation studies, which also showed that there was no interference of the excipients. The limits of quantitation and detection were 2 and 0.41 pg/mL, respectively. The method was applied for the analysis of ezetimibe pharmaceutical formulations, and the results were compared to those of the liquid- chromatography method.