Comparative bioavailability and pharmacokinetics of sirolimus tablets in healthy Chinese volunteers

摘要

Objectives: Although siro-limus tablets and oral solutions have been used in clinical practice, no study has been reported on the pharmacokinetics and bio-availability of a single-dose of sirolimus tablets in healthy Chinese volunteers. The purpose of this study was to compare the bioavailability and pharmacokinetic (PK) properties of two different 1-mg sirolimus tablets in healthy Chinese male volunteers and evaluate whether a generic tablet of sirolimus meets the criteria for bioequiva-lence from the State Food and Drug Administration (SFDA) of China when compared with a reference product. Materials and methods: A total of 24 healthy Chinese volunteers was eligible for this 6 mg singledose, randomized-sequence, open-label, 2-period crossover study. Blood samples were collected before dosing and at 0.25, 0.50, 0.75, 1.0, 1.5, 2, 3, 4, 8, 12, 24, 48, 72, 120, 168, 216, and 264 hours after dosing. Whole blood sirolimus concentration was analyzed by a validated liquid chro-matography- tandem mass spectrometry (LC-MS/MS) method. Pharmacokinetic properties of sirolimus were assessed using noncompartmental analysis. Results: The mean (range) Cmax values of the test and the reference were 15.25 (8.48-24.40) and 13.43 (7.90-22.90) ng/ml; AUC0-t values were 475.65 (293.33-1049.86) and 451.96 (221.52-809.11) ng/h/ml. The medians (range) t max values were 2.0 (1.0-8.0) and 2.0 (1.0-8.0) hours, respectively. The 90% confidence intervals (CIs) for the ratios of Cmax, AUC 0-264, and AUC0-∞ were 103.7-124.4%, 97.5-113.6%, and 98.0-114.8%, respectively. Conclusion: In this singledose crossover study the test sirolimus tablets met the criteria for bioequivalence in terms of both rate and extent. Each siroli-mus formulation was well tolerated during the study.