Abstract: AIM:To study the pharmacokinetics of secnidazole vagina effervescent tablets in healthy volun- teers.METHODS :250, 500 and 750 mg secnidazole vagina effervescent tablets were used in single-dose groups;500 mg secnidazole vagina effervescent tablets were used for 7 days in multi-dose group .The concentra- tions of secnidazole in plasma were determined by HPLC . The parameters of pharmacokinetics were calculated by DAS software .RESULTS AND CONCLUSION:The pharmacokinetic parameters after administration of a single dose of secnidazole vagina effervescent tablets( 250, 500, 750 mg) in health married female volunteers were as fol- lows :T_{1/ 2β} were 18 .84, 15 .25, and 21 .86 h, in accor- dance with the literatures ;T_max were 12 .22, 14 .00, and 18 .00 h ;C_max were 3 .58, 5 .42, and 8 .00 mg·L ^-1 ; AUC were 103 .52, 190 .99, and 296 .92 mg·h^-1·L ^-1 , respectively.The absorption of secnidazole vagina effer- vescent tablets was slower and lower than oral tablets . The systemic actions and adverse reactions were fewer and rudimental concentrations were higher so as to show more local actions .The pharmacokinetic parameters after ad- ministration of multi doses of secnidazole vagina efferves- cent tablets ( 500 mg ) were as follows :T_1/2β =22 .74 h, C_max =14 .30 mg·L^-1 , T_max =11 .60 h, and AUC = 520 .14 mg·h^-1·L ^-1 .C_max and AUC were higher than the results of a single dose.These showed that the drug can cumulate after a long-time administration because of its long half-life and required more caution .

Key words: secnidazole , effervescent tablets , phar- macokinetics, plasma concentration , high performance liquid chromatography (HPLC)