COMPARATIVE BIOAVAILABILITY STUDY OF 2 ORAL OMEPRAZOLE FORMULATIONS AFTER SINGLE AND REPEATED ADMINISTRATIONS IN HEALTHY-VOLUNTEERS

Objective: Two oral enteric-coated pellet formulations of omeprazole, Pepticum(R) (test formulation) and Mopral(R) (reference), were adminis tered to 24 healthy volunteers for 5 days at a daily dose of 20mg omep razole in order to investigate the comparative bioavailability of the two formulations. Results: The data obtained in this study demonstrate d the bioequivalence of the two formulations. No statistical differenc es were observed for the area under the plasma concentration-time curv e (AUC(0-t)), the parameter to which the inhibition of acid secretion induced by omeprazole is directly related. Differences observed in max imum plasma drug concentration (C-max) at day 1 for both formulations were not statistically significant. At steady-state, the differences f ound in C-max were associated with a p-value <0.05 with the 90% confid ence interval lying between the acceptance range (70 to 140%). Regardi ng time to reach C-max (t(max)), p < 0.01 was found both after single and repeated doses. In both cases, Pepticum(R) showed a delay in reach ing C-max compared with Mopral(R): 2.15 +/- 1.11 vs 1.48 +/- 0.52h (da y 1) and 1.94 +/- 0.66 vs 1.31 +/- 0.75h (day 5). Conclusion: This stu dy confirmed the reported increases in AUC and C-max after repeated ad ministrations, the important intersubject variability and the excellen t biological and clinical tolerability of both formulations.