Enantioselective analysis of omeprazole in pharmaceutical formulations by chiral high-performance liquid chromatography and capillary electrophoresis

We developed two sensitive and simple assay procedures based on high-performance liquid chromatography and capillary electrophoresis (CE) for the enantioselective analysis of omeprazole in pharmaceutical formulations. Rac-omeprazole and (S)-omeprazole were extracted from commercially available tablets using methanol: NaOH 2.5 mol L-1 (90:10, v/v). Chiral HPLC separation of omeprazole was obtained on a CHIRALPAK AD column using hexane: ethanol ( 40: 60, v/v) as the mobile phase and detection at 302 nm. The resolution of omeprazole enantiomers by CE was carried out using 3% sulfated beta-cyclodextrin in 20 mmol L-1 phosphate buffer, pH 4.0 and detection at 202 nm.