Bioequivalence of two tablet formulations of atenolol after single oral administration in healthy volunteers

The pharmacokinetic parameters of two oral formulations of 100 mg tablets o f atenolol (CAS 29122-68-7; Azectol(R) as test and another commercially ava ilable preparation as reference) were compared in an open-label, randomized , single oral dose, two-period cross-over design to 17 healthy volunteers u nder fasting conditions. Serial blood samples were collected prior to each administration and at 17 points within 36 h after dosing. Plasma concentrat ions of atenolol were measured by a validated HPLC assay with fluorometric detection. The parametric 90 % confidence intervals of the geometric mean v alues of the test/reference ratios were 94.4 % to 112.9 % (point estimate: 103 %) for AUC(0-infinity) 93.7 % to 112.8 % (point estimate: 103 %) for AU C(0-36), and 88.3 % to 112.1 % (point estimate: 100 %) for C-max, within th e acceptance criteria for bioequivalence (80 %-125 %). T-max values were an alyzed by the nonparametric Wilcoxon test and the difference was not statis tically significant. Therefore, it is concluded that the test and reference atenolol formulations are bioequivalent for both the extent and the rate o f absorption.