Pharmacodynamics and kinetics of omeprazole MUPS 20 mg and pantoprazole 40 mg during repeated oral administration in Helicobacter pylori-negative subjects

Background: Omeprazole has become available in a tablet formulation, a Multiple Unit Pellet System (MUPS) containing a large number of small individually enteric-coated micropellets. Aim: To compare the acid-inhibitory effect of omeprazole MUPS 20 mg with pantoprazole 40 mg and to describe the pharmacokinetics of both drugs following administration on day 1 and day 6. Methods: Randomized, two-way crossover study, Sixteen Helicobacter pylori-negative healthy subjects, whose gastric acidity fell below pH 4 for 70% of a 24-h baseline period were included, Intragastric pH was measured continuously, Results: On day 1 both drugs significantly raised median 24-h gastric pH compared to baseline. Median pH and percentages of time above pH 3 and 4 on day 1 and day 6 of administration were not significantly different, with the exception of median daytime pH on day 6, which was significantly higher with omeprazole (4.65 vs. 4.05), AUC and C-max of omeprazole were significantly increased on day 6. AUC and C-max of pantoprazole were not significantly increased. Conclusions: No significant difference in acid-inhibitory effect on day 1, On day 6 median daytime pH was significantly higher with omeprazole MUPS, but the percentages of time spent above pH 3 and 4 were not significantly different. The significant increase in bioavailability of omeprazole may contribute to the increased effect on day 6.