Pharmacokinetics and relative bioavailability of two allopurinol tablets in healthy Chinese volunteers

To evaluate the pharmacokinetics and relative bioavailability of two allopurinol tablets in healthy Chinese volunteers. A single-center, randomized, cross-over, two-period study design was conducted in healthy male subjects who were identified as not carrying the HLA-B*58:01 allele. Under fasting conditions, a single oral dose of 300 mg test or reference tablets was given with a 1-week washout period. The blood samples were collected for up to 12 hours after the administration and the plasma concentrations of allopurinol were determined by high performance liquid chromatography. Subject interviews and physical examinations were done over regular intervals to monitor the adverse events. 18 subjects were enrolled in the study, and none dropped out. The main pharmacokinetic parameters of allopurinol test and reference preparations were as follows: AUC was 6,725.1 ± 1,390.0 ng×h×mL and 6,425.6 ± 1,257.6 ng×h×mL ; AUC was 7,069.1 ± 1,503.2 ng×h×mL and 6,750.6 ± 1,347.7 ng×h×mL ; t was 1.3 ± 0.8 hours and 1.3 ± 0.8 hours; C was 2,203.7 ± 557.4 ng×mL and 2,310.8 ± 662.8 ng×mL ; and T was 2.0 ± 1.6 hours and 1.7 ± 0.7 hours. The relative bioavailability was 105.1 ± 12.6%. The 90% confidence intervals for the geometric mean ratios (test/reference) of C , AUC , and AUC of both preparations fell within the bioequivalence acceptance criteria (80 - 125%). No adverse events were found or reported during the study. The test allopurinol preparations and the reference preparations are bioequivalent and both are well tolerated. .