Pharmacokinetics and bioequivalence of two metoprolol succinate extended release tablets in healthy Chinese subjects under fasting and fed conditions

The aims of this study were to evaluate and compare the pharmacokinetic profiles and establish bioequivalence of test and reference metoprolol succinate extended-release (ER) tablets in healthy Chinese subjects under fasting and fed conditions. Subjects were randomly assigned to either the fasting or the fed group and also to one of the two treatment sequences (test-reference or reference-test), according to which they received a single 47.5-mg dose of the test or reference metoprolol ER tablet in the study periods. During each period, blood samples were collected at pre-dose and at intervals up to 48 hours after dosing. Plasma concentrations of metoprolol were determined by liquid chromatography. The safety of both ER tablets was monitored throughout the study. 60 subjects were enrolled and all completed the study, with 30 participants each in the fasting and fed groups. In both groups, the 90% confidence intervals for AUC , AUC , and C were within the acceptable bioequivalence range (80 - 125%). There were no significant differences in adverse event (AE) reporting between the subjects receiving test or reference ER tablet. No serious AEs occurred during the study period. The test metoprolol ER tablet was bioequivalent to the reference metoprolol ER tablet (Betaloc ZOK) in healthy Chinese subjects measured under both fasting and fed conditions. Both formulations were well tolerated by all study participants.