Abstract: AIM: To evaluate the bioequivalence of the two preparations of apixaban tablets administered once orally under fasting and fed conditions. METHODS: The study was designed as randomized, open, self-crossover, and twenty four healthy volunteers were recruited respectively in fasting and fed conditions. Subjects were assigned to receive a single oral of the test or reference formulation per period at a dose of 2.5 mg. The plasma apixaban concentration was analyzed by LC-MS/MS. The major pharmacokinetic parameters were calculated by WinNonlin 6.4 and the bioequivalence was evaluated.RESULTS:The main pharmacokinetic parameters of a single oral apixaban under fasting condition for T and R were as follows: Cmax (80±14) and (87±21) ng/mL, AUC0-t (713±136) and (733±142) h·ng·mL-1, AUC0-∞ (722±143) and (741±142) h·ng·mL-1, tmax 2.5 h and 2.5 h, t1/2 (9±8) and (8±6) h. The relative bioavailability was 97.16% for AUC0-t, 97.20% for AUC0-∞. The main pharmacokinetic parameters of a single oral apixaban under fed condition for T and R were as follows: Cmax (70±13), (72±13) ng/mL; AUC0-t (642±130), (690±135) h·ng·mL-1; AUC0-∞ (652±129), (704±138) h·ng·mL-1. tmax 2.5 h and 2.5 h, t1/2 (8±4) and (12±9) h. The relative bioavailability was 93.03% for AUC0-t, 92.62% for AUC0-∞. CONCLUSION: The test preparation of apixaban tablets is bioequivalent to the reference preparation under both fasting and fed conditions.

Key words: apixaban, LC/MS-MS, bioequivalence, pharmacokinetics