Pharmacokinetics And Bioequivalence Of Three Different Sulfadiazine Suspensions In Broilers

The article is designed to study the pharmacokinetics and bioequivalence of three different sulfadiazine suspension (Doge, Tribrissen and Sulfaprim) in broilers. Forty-five broilers were used following a single dose oral (20mg/kg b.w.) administration of compound sulfadiazine suspension, and randomLy divided into three groups. Blood samples were obtained at different time intervals after administration respectively. The concentration of sulfadiazine and thrimethoprim in plasma were determined by reverse high performance liquid chromatography (HPLC). The concentration-time date of sulfadiazine and trimethoprim in plasma were analyzed by kinetic compute program.Working conditions of HPLC were as follows:mobile phase was acetonitrile-0.01mol/L Potassium dihydrogen phosphate (14:86), flow rate was1.0mL/min, column temperature was40℃, detection wavelength was set at240nm. Under given chromatography conditions, the concentration of sulfadiazine in broilers plasma showed a good liner coefficient relation within the range of0.06～10mg/L, which correlation coefficient were morn than0.9991. The recoveries were higher than97.62%. The intra-day coefficients of variation and inter-day coefficients of variation were less than2.37%. The limit of detection(LOD) was0.03mg/L, and the limit of quantification(LOQ) was0.06mg/L. The concentration of trimethoprim in broilers plasma showed a good liner coefficient relation within the range of0.1～1mg/L, which correlation coefficient were morn than0.9992. The recoveries were higher than90.75%. The intra-day coefficients of variation and inter-day coefficients of variation were less than5.44%. LOD and LOQ were0.05mg/L and0.1mg/L, respectively.Broilers were administered orally with a single of20mg/kg body weight of compound sulfadiazine suspension (sulfadiazine:trimethoprim=5:1). The main pharmacokinetic parameters in the test preparation (Doge) and reference preparations (Tribrissen and Sulfaprim) were shown as following:Cmax were10.60,15.64,11.45mg/L; Tmax were4.93,3.43,3.87h; AUC were89.31,119.54,86.81mg/L/h; Clearance were7.94,3.23,6.54L/kg/h; Vz were3.57,1.16,10.43L/kg.The results showed that, calculated with AUC. the relative bioavailability of the test preparation were74.71%and102.88%. The analysis of variance and95%confidence interval methods were used to judge the bioequivalence between the reference and test preparation. Compared with reference preparations, the95%confidence interval of the main pharmacokinetic parameters of test preparation were as following:95%CI of Cmax were0.72～1.02and0.70～1.28,95%CI of AUC were0.90～1.08and0.92～1.13. The results of statistical analysis showed that there was no significant difference among Doge, Tribrissen and Sulfaprim, which were proven to be bioequivalent.