Abstract: AIM: To compare the pharmacokinetics and bioavailability of ketoprofen sustained release tablets (ST) with those of regular tablets (Reference tablet, RT) in 10 healthy volunteers after single and repeated oral administrations in randomized crossover design. METHODS: A sensitive and rapid HPLC method was used to determine the serum ketoprofen concentration. RESULTS: The results from single oral dose in 8 healthy volunteers indicated that the C_max of RT was significantly higher than that of ST. The T_max and t_1/2ke of ST were significantly longer than those of RT (P<0.01). The relative bioavailability of ST was found to be 9713%. As there was no difference in the AUC between the two preparations, it can be concluded that the new sustained release tablet was bioequivalent to RT. The C_min of ST and RT at steady state were 0.401μg·mL^-1 and 0.190 μg·mL^-1, respectively, with a significant difference (P<0.01) between them. The ketoprofen concentration peaktrough ratio (PTR) and the degree of fluctuation (DF) of ST were significantly smaller than those of RT. CONCLUSION: The new sustained release tablet showed less fluctuation of peak and trough serum drug concentrations than those of the regular tablet at steady state and exhibited good sustained release property.