Abstract
Omeprazole (CAS 73590-58-6) effectively suppresses the gastric acid secretion in the
parietal cells of the stomach and is a widely prescribed proton pump inhibitor in
Bangladesh. The increasing number of omeprazole containing products available in the
market raises questions of therapeutic equivalence and/or generic substitution which
are yet to be conducted with Bangladeshi population. The aim of the study is to assess
the bioequivalence and pharmacokinetic properties of two oral formulations of 20 mg
omeprazole capsule, the reference product and Omep-20 as test product using serum
data. The randomized, two-way crossover study was conducted on 24 healthy male subjects
in compliance with the Declaration of Helsinki and ICH guidelines. Subjects were assigned
to receive test and reference as a single dose of 20 mg capsule under fasting condition,
following a washout period of one week. After oral administration, blood samples were
collected at various time intervals and analyzed for omeprazole concentrations using
a validated HPLC method. The pharmacokinetic parameters were determined by non-compartmental
method. From serum data, the obtained values for test and reference products were
648.07 ± 216.27 and 632.69 ± 257.01 ng/ml for Cmax; 2 012.24 ± 634.48 and 1907.86 ± 761.91 ng · h/ml for AUC0–24; 2105.21 ± 623.79 and 1 979.18 ± 748.12 ng · h/ml for AUC0–∞ respectively. No statistically significant differences were observed between two
formulations by analyzing different pharmacokinetic parameters in terms of period,
sequence or formulation. From the paired t-test, no significant differences between
two formulation were observed (p > 0.05). The 90% confidence intervals of Cmax, AUC0–24 and AUC0–24 were found to be 91.59% to 122.60%, 101.86% to 116.78% and 102.77% to 116.68% respectively
which are within the FDA accepted limits for bioequivalence (80%–125%). Finally it
can be concluded that both products are bioequivalent in terms of rate and extent
of drug absorption and therefore interchangeable.
Key words
CAS 73590-58-6 - Gastric disorders - Omep-20 - Omeprazole, Bangladeshi population,
bioequivalence, pharmacokinetics - Proton pump inhibitors
