Bioequivalence of Omeprazole in Healthy Volunteers and the Determination of its Metabolites in Urine

Aim To develop a method to determine the pharmacokinetics of omeprazole capsules in human plasma by HPLC for the study of bioavailability in Chinese healthy volunteers and to determine its metabolites in urine. Methods A random-ized two-way cross-over was used for two oral groups.Volunteers took a single oral dose of 40mg tested omepazole and reference omepazole respectively. Then omeprazole concentrations in plasma and metabolites in urine were detected by HPLC. The pharmacokinetic parameters as well as relative bioavailability were analyzed by software DAS.Results The results showed that the plasma concentration-time curves of the two omeprazole capsules conformed to a two compartment open model . The main parameters were as follows:Tmax was (1.94 ±0.86)h and (2.11±0.73)h;Cmax was (796.57±336.63)ng·ml-1 and (776.30±341.55)ng·ml-1, AUC0～12 was (1 755.86±1 169.44)ng·h·ml-1 and (1 749.90±61 241.73)ng·h·ml-1, respectively. The relative bioavailability of omeprazole capsule was (105.00±30.08)%. Conclusion The result of the statistical analysis showed that the two formulations were bioequivalent .