Pharmacokinetics of Esomeprazole Magnesium After Single Oral Doses in Healthy Subjects: Bioequivalence Study and Food Effects

This study was designed to evaluate the bioequivalence of the newly developed delayed-release oral suspension (test) 40 mg esomeprazole magnesium compared to its marketed counterpart (40 mg; reference) in healthy adult Chinese subjects. We conducted randomized, open-label, two-period, single-dose, two-way crossover trials over a 7-day washout period, comprising a fasting trial and a fed trial. The subjects were administered the test or reference products in a 1:1 ratio at random throughout each period. Then, in the next session, they received the alternate products. Liquid chromatography-tandem mass spectrometry and WinNonlin software were used to assess the bioequivalence of esomeprazole peak plasma concentration (Cmax ) and area under the concentration-time curve (AUC). Overall, 33 subjects participated in the fasting trial and 42 subjects participated in the fed trial. Under both situations, the 90% confidence interval for the ratio of geometric means of Cmax , AUC0-t , and AUC0-∞ were within equivalence ranges (80%-125%). In these trials, no severe adverse events or protocol violations were observed. Moreover, when esomeprazole was administered while fed, the tmax was delayed, and both Cmax and AUC were reduced. The results of this research suggest that the test and reference formulations were bioequivalent under fasting and fed states.