Abstract: Aim To study the pharmacokinetics and relative bioavailabilty of tramadol hydrochloride tablet. Methods Twelve male Chinese healthy volunteers received a single oral dose of tramadol hydrochloride tablet(THT) 100mg and tramadol hydrochloride capsule(THC) 100mg in a random crossover design. Drug concentrations in plasma were determined by HPLC.Results The concentration time profile conformed to an open two-compartment model. The T_1/2 and AUCo-24 of two products were (7.69+3.74) h and (7.66士3.41) h,(3100土1165) μg·h·L^-1 and (3212士1260) μg·h·L^-1,respectively. No significant difference was observed in pharmacokinetic parameters bet ween tested and reference preparations(P>0.05).Conclusion The THT and THC have bioequivalence.

Key words: tramadol, pharmacokinetics, relative bioavailability