Pharmacokinetics and Bioequivalence of 20 Mg Omeprazole Capsule in 24 Healthy Korean Male Volunteers.

Objective: A randomized, two-way, crossover bioequivalence study in 24 healthy Korean male volunteers was conducted to compare bioequivalence of two brands of 20 mg omeprazole Capsules, Hutex omeprazole (R) (Hutex Pharm Co. Korea) as a test and Yuhan Losec (TM) (Yuhan Co. Ltd., Korea) as a reference drug. Volunteers and methods: Subjects were administered single dosage of I capsule of 20 mg of each formulation with 240 ml of water after 10 hs overnight fasting on 2 treatment days separated by one-week washout period. After dosing, serial blood sampling was held during 9 lis. Plasma was analyzed for omeprazole by a validated HPLC method with ultraviolet detection in the range of 10 similar to 1,000 ng/ml with the lowest limit of quantification of 10 ng/ml. Results: Several pharmacokinetic (PK) parameters were determined from the plasma samples, and data from reference and test formulations in the plasma were represented such as AUC(0-t) (1,223.3 vs 1,284.3 ng x h/ml), AUC(0-infinity) (1,311.1 vs 1,410.0 ng x h/ml), C-max (598.7 vs 598.1 ng/ml), t(max) (1.9 vs 1.9 h), t(1/2) (1.3 vs 1.4 h) and Ke (0.67 vs 0.67 h(-1)), respectively. AUC(0-t), AUC(C-infinity) and C-max were tested for bioequivalence after log-transformation of plasma data. PK parameters with 90% confidence interval (Cl) of test/reference ratio based on ANOVA analysis were 0.961 similar to 1.135 for AUC(0-t), 0.968 similar to 1.144 for A UCC-infinity and 0.951 similar to 1.117 for C-max. Conclusions: PK parameters with 90% Cl were within the bioequivalence range of 80-125% of FDA statistical limit. Therefore, both omeprazole formulations were bioequivalent during fasting state in these healthy Korean male volunteers.