Abstract
The study was conducted in order to assess the bioequivalence of two capsule formulations
(test and reference) containing 20 mg of omeprazole (5-methoxy-2-[[4-methoxy-3,5-dimethyl-2-pyridinyl)
methyl] sulfinyl]-lH-benzimidazole, CAS 73590-58-6). Fifty healthy male and female
volunteers were treated in a single-centre, randomised, repeated-dose (once daily
for six consecutive days), open-label, two-way crossover study, with a washout period
of at least 9 days between treatments. Plasma samples were collected up to 12 h post-dosing
for the determination of omeprazole by HPLC with photodiode array detector (DAD).
The evaluation of bioequivalence was based on the following pharmacokinetic parameters
that were calculated by standard non-compartmental methods: area under the plasma
concentration-time curve from zero to the time of the last quantifiable concentration
(AUCt) and that extrapolated to infinity (AUC) and the maximum observed concentration (Cmax). The 90% confidence interval around the ratios (test/reference) (obtained by analysis
of variance, ANOVA) were 0.92-1.04 for Cmax, 0.88-1.05 for AUCt, and 0.88-1.05 for AUC, i.e., within the predefined acceptable range for the conclusion
of bioequivalence. The study indicated that the test and reference formulations containing
20 mg of omeprazole are bioequivalent in terms of both the rate and extent of bioavailability.
Key words
CAS 73590-58-6 - Omeprazole, bioequivalence, pharmacokinetics - Proton pump inhibitors
