Abstract: Aim The pharmaco kinetics and relative bioavailability of domestic film-coating special shaped tablet of acetaminophen were studied.Methods A single oral dose of 500 mg of the two formations (test and reference preparation)was given to 10 healthy male volunteers according to randomized 2-w ay cross-over design,blood sample was with drawn 10 hours after administ ration,and plasma concent rations of acetaminophen were assayed by a high performance liquid chromtography (HPLC)method.Results The concentration-time curves of the two preparations fitted to a one-compartment model with first order absorption and lag time.The main pharmacokinetic parameters of the tested preparation were as follows:C_max=5.51±1.24 mg/L,T_peak=1.03±0.43h,T_{1/2k a}=0.27±0.16h,T_1/2ke =2.60±0.51h,AUC_0~t =23.69±4.08 mg·h·L^-1,MRT=3.65±0.22 h.Conclusion The relative bioavailability of the test preparation is 102.5±13.3% to the reference preparation.The bioavailabity of the two kinds of acetaminophen is equal,showing that the two kinds of preparations are bioequivalent preparations.

Key words: film-coating special shaped tablet of acetaminophen, bioavailality, pharmacokine tics, HPLC