2种头孢氨苄片在比格犬体内的药代动力学及生物等效性试验

【目的】研究头孢氨苄片受试制剂和参比制剂在比格犬体内的生物等效性。【方法】采用双周期和双序列交叉设计,将22只健康比格犬随机分成2组,按30 mg/kg BW分别单剂量口服头孢氨苄片受试制剂Trolevis~?300和参比制剂Rilexine~?300,于给药前(0 h)和给药后0.5、1、1.5、2、2.5、3、4、6、8、12、17和24 h从臂头静脉采血。对超高效液相色谱串联质谱(UPLC-MS/MS)方法进行特异性、线性、检测限、准确度、精密度、稳定性等方法学考察。利用建立好的UPLC-MS/MS方法测定血浆中的药物浓度,并用WinNonlin^TM 8.1软件对药代动力学参数进行分析计算。【结果】方法学结果显示,在100～5 000 ng/mL浓度范围内相关性良好,相关系数(R²)≥0.99,标准曲线方程为y=10.6828x-176.481;高、中、低3个浓度的相对回收率平均值分别为105.63%、104.35%和102.40%;日内和日间变异系数均<15%;检测限为50 ng/mL,定量限为100 ng/mL。药代动力学结果...

Pharmacokinetics and Bioequivalence of Two Cephalexin Formulations in Beagle Dogs

[Objective] The purpose of the experiment was to study the bioequivalence of cephalexin test and reference formulations in Beagle dogs. [Method] Twenty-two Beagle dogs were randomly allocated to two equal-sized treatment groups in a randomized dual-cycle and dual-sequence cross-over design. The test (Trolevis^®300) and the reference (Rilexine^®300) formulations were orally administered in a single dose of 30 mg/kg BW. Blood samples were collected from brachiocephalic vein at 0, 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 12, 17 and 24 h after administration. The specificity, linearity, detection limit, accuracy, precision, and stability of UPLC-MS/MS method were investigated. The concentration of cephalexin in plasma was determined by UPLC-MS/MS. The pharmacokinetic parameters were analyzed and calculated with WinNonlin^TM 8.1. [Result] The methodological results showed good correlation over the concentration range of 100-5 000 ng/mL with a correlation coefficient (R²) ≥ 0.99 and a standard curve equation of y=10.6828x-176.481. Relative recoveries were 105.63%, 104.35% and 102.40% for high, medium and low concentrations. Coefficient variations of intra-day and inter-day were all less than 15%, and the limit of detection and the limit of quantification were 50 and 100 ng/mL, respectively. The pharmacokinetic parameters of the two groups were as follows:T_max were (1.77±0.55) and (2.70+4.68) h, C_max were (28.09±5.09) and (26.82±7.94) μg/mL;T_1/2 were (3.39±1.43) and (3.12±1.05) h;AUC_0-t were (121.81±25.80) and (116.34±36.30) μg·h/mL. The plasma profiles of cephalexin following the administration of both formulations were similar. And the ratio of the average C_max, AUC_0-t and AUC_0-∞ of the test/reference preparation were 99.51%, 99.27% and 99.30% respectively, the 90% CI all fell between 80.00%-125.00%. [Conclusion] The UPLC-MS/MS method established in this experiment was accurate and reliable, and could be used to determine the concentration of cephalexin. The two formulations were bioequivalent for cephalexin, and could be used clinically for the treatment of related diseases.