Abstract: AIM: To establish a reversed phase high performance liquid chromatography (RP-HPLC) method for determination of omeprazole in human plasma and the pharmacokinetic study of omeprazole in 9 healthy volunteers. METHODS:The RP-HPLC method was used. The separation was carried out using krumasil C18 (4.6 mm ×200 mm, 5 μm) column with mobile phase of acetonitrile and 0.01 mol·L^-1 phosphate buffer (55:45, v/v).The pH of the water phase was adjusted to 7.5 with triethylamine at flow rate of 1.3 ml·min^-1.The detection wavelength for omeprazole was 302 nm.A single oral dose 40 mg of omeprazole was given to 9 healthy males.RESULTS: The linear range for omeprazole was 10-2 000 μg·L^-1 (r =0.9999).The quantitation limit for omeprazole was 10 μg·L^-1.The relative recoveries were 92.35%, 96.90% and 100.04%, and RSD for intra-day and inter-day were both less than 15%.The pharmacokinetic analysis of omeprazole was studied.It was found to be fit for a one-compartment openmodel.CONCLUSION: The method is sensitive, accurate and simple, and suitable for the study on pharmacokinetic of omeprazole in human.

Key words: omeprazole, concentration in plasma, RP-HPLC, pharmacokinetics