Bioavailability and pharmacokinetics of anastrozole in healthy male volunteers / 中国药理学通报

ABSTRACT

AIM: To evaluate bioavailability and pharmacokinetics of domestic and imported anastrozole tablets. METHODS: Twenty Chinese healthy male volunteers were enrolled in a randomized crossover study with a single oral dose of 2 mg of the two formulations respectively. The anastrozole in plasma was measured by gas chromatography with electron-capture detection. The linear range was from 1. 325 to 106 μg·L-1 plasma. The extraction recovery rates for plasma concentration of 5.3, 21.2 and 53.0 μg·L-1 were 76.8%, 87.0% and 78.7% respectively. Inter-day and intra-day precisions of the method were < 9%. Area under concentration-time curve (AUC0-t), maximum plasma concentration (Cmax) and reach peak time (Tmax) were evaluated by variance analysis and two one-side t-test. RESULTS: A two-compartment model was adopted in anasreozole plasma concentration-time data analysis. The main pharmacokinetic parameters of domestic and imported anastrozole tablets such as Cmax, Tmax, AUC0-t and T1/2β were (36.5 ± 6.9) and (35.6 ± 9.4) μg·L-1, (1.56±0.41) and (1.53±0.49) h, (1403.6 ± 321.2) and (1371.6±329.4) μg·h·L-1, (42.57±10.15) and (43.41±8.59) h, respectively, and there were no significant differences between the two formulations. CONCLUSION: Domestic and imported anastrozole tablets are of bioequivalence. The relative bioavailability of the domestic tablet is (102.7±5.6) %.