OBJECTIVE:To evaluate the bioequivalence of domestic secnidazole tablet,capsule and imported secnidazole tablet in healthy volunteers.METHODS:18healthy volunteers were randomly divided into3groups according to a triple-cross design,all the volunteers were given a single dose of1g secnidazole,the interval for washout period of3times adminis?tration was14days.The plasma drug concentration of secnidazole was determined by HPLC-UV.RESULTS:The main pharmacokinetic parameters of homemade tablet and homemade capsule and imported tablet were as follow,t max were(2.00?1.93),(2.67?2.14)and(1.54?1.53)h respectively,t 1/2 were(28.56?4.98)、(29.69?6.81)and(27.16?5.06)h,C max were(25.50?2.74),(24.27?3.76)and(25.64?4.10)?g/ml respectively.AUC 0～t were(736.03?73.20),(704.78?88.51)and(737.77?76.02)(?g?h)/ml respcetively.AUC 0～∞ were(886.36?114.50),(864.57?172.27)and(870.64?100.21)(?g?h)/ml respectively.The relative bioavailability of homemade tablet was(100.02?6.73)%,and that of homemade capsule was(95.91?10.66)%.CONCLUSION:3preparations of secnidazole are bioequivalent.