Pharmacokinetics and relative bioequivalence of tramadol hydrochloride in healthy volunteers

    WANG Meng, WEN Aiª² Dong, ZHAO Lei, WU Yin, ZHANG Sanª² Qi, Li Hongª² Li£¬SHI Ru

    Department of pharmacy, Xijing Hospital, Fourth Military Medical University, Xi¬ðan 710033, China

    ¡¾Abstract¡¿ AIM: To compare the pharmacokinetic parameters and relative bioavailability of domestic and imported tramadol hydrochloride tablets so as to ensure quality of the medicine. METHODS: An open, randomized, twoª² period crossover study with a twoª² week washout interval was performed in 18 healthy volunteers. Concentrations of tramadol in serum were assayed by HPLCª² FR method. The pharmacokinetics parameters, AUC, Cmax and Tmax, were analyzed by two oneª² side t test. RESULTS: The concentrationª² time course after medication conformed to a 1ª² compartment open model with a first order absorption. The AUC(0ª² 24 h), Cmax and Tmax of tramadol were (2173¡À680) and (2252¡À597) ¦Ìg¡¤h/L£¬(223¡À79) and (229¡À65)¦Ìg/L, (2.28¡À0.67) and (2.33¡À0.67)h respectively. The relative bioavailability of tramadol was 96.40%. CONCLUSION: Two tablets are bioequivalent. ......