Bioequivalence evaluation of two rosiglitazone tablet formulations

A randomized, two-period, two-sequence, crossover study was conducted on 28 healthy male volunteers to compare the bioavailability of two rosiglita-zone (CAS 122320-73-4) tablet formulations, a test and a commercially available original preparation (reference), under fasting conditions. The two preparations were given in a dose of 8 mg with a 7-day washout period between the two preparations. Eighteen blood samples were collected over 24 h, plasma rosiglitazone concentrations were determined by locally validated high performance liquid chromatography (HPLC) assay, and pharmacokinetic parameters were analyzed by the standard non-compartmental method. The mean+/-SD of AUC0-->t, AUC0-->infinity, Cmax, Tmax, and t1/2 were 4.80+/-1.89 and 4.76 +/-1.94 microg x h/ml, 5.17+/-2.11 and 5.08 +/- 2.27 microg x h/ml, 0.93+/-0.24 and 0.99+/-0.34 microg/ml, 1.0 +/-0.4 and 0.8+/-0.5 h, and 5.0+/-2.0 and 5.0+/-2.0 h for the test and reference formulation, respectively. ANOVA did not show significant formulation, period, or sequence effect for any of the pharmacokinetic parameters. The 90 % confidence intervals of the mean differences between log-transformed values of the two formulations were 93.09 % to 109.73 %, 94.04 % to 111.70 %, and 89.70 % to 103.24 % for AUC0-->t, AUC-->infinity, and Cmax, respectively. It is concluded that the two formulations are equivalent in relation to the rate and extent of absorption.