Bioequivalence of Two 6-Mercaptopurine Tablet Formulations in Healthy Fasting Chinese Volunteers.

The supply of branded 6-mercaptopurine (6-MP) is limited in China, necessitating the local production and clinical evaluation of generic alternatives. We evaluated the in vivo bioequivalence (BE) of a new generic mercaptopurine tablet (50 mg) formulation by comparing peak plasma concentration and area under the concentration-time curve (AUC) with a branded 6-MP formulation as the reference in 36 healthy fasting Chinese adults. The in vivo BE was evaluated by the average BE test. The safety parameters of the test and reference formulations were also evaluated. The geometric mean ratios for AUC over the dosing interval and AUC from time zero to infinity were 104% and 104%, respectively, of the reference values, while the point estimate of the geometric mean ratio for peak plasma concentration was 104% of the reference value. The test and reference formulations in this study were both deemed safe as only 23 Grade 1 adverse events were observed in 13 of 36 subjects. The test and reference formulations of 6-MP tablets meet the regulatory criteria for BE in healthy fasting Chinese adults.