【作者】 王旭；

【导师】 王大菊；

【作者基本信息】 华中农业大学 ， 基础兽医学， 2001， 硕士

【摘要】 本文采用HPLC法为定量手段，研究替硝唑在三黄鸡体内的单剂量（30mg／Kg. b. w）静注和口服的药物动力学过程以及多剂量给药后组织中的残留。静注和口服给药后，分别在0.08～24h和0.25～24h定时从翼静脉采血，分离血浆，—20℃避光保存。血浆中药物用二氯甲烷：甲醇（98：2v/v）提取，有机层于50～55℃水浴下氮气吹干，残渣以三蒸水溶解，用反相高效液相色谱法（RP-HPLC）测定。检测采用Spectrasystem HPLC系统，YWG-C₁₈柱（250×4.6mm，10μm），以甲醇：20％乙腈：水（25：25：50 v/v）为流动相，流速1.0ml／min，检测波长318nm。替硝唑对照品的最低检测限为0.0625μg／ml，浓度在0.125～64.0μg／ml时与峰面积呈良好线性关系，线性方程为y=72.57x-22261.65（r=0.9998）。替硝唑水溶液浓度在0.125、4.0、64.0μg／ml时，日内、日间变异系数分别为4.27％和6.21％，1.47％和2.24％，0.08％和1.03％。血浆标准曲线线性范围为0.2～51.2μg／ml，线性方程为y=38.34x-8167.38（r=0.9989）。血浆中替硝唑浓度在0.2、1.6、51.2μg／ml时，日内、日间变异系数分别为3.26％和7.58％，1.28％和5.72％，0.20％和2.31％，平均回收率大于90％。鸡单剂量静注和口服给药后的血药浓度—时间数据及药物动力学参数用PKANALYST软件包处理。静注给药后的药—时过程符合二室开放模型，其主要药动学参数为：分布半衰期(t_1/2α)为0.279h，消除半衰期(t_1/2β)4.705h，中央室表观分布容积（Vc）0.857L／kg，稳态表观分布容积(V_dss)1.293L／kg，体清除率（Cl_b）0.206L／h．kg，药时曲线下面积（AUC）153.280mg．h／L。口服给药的药—时数据符合一级吸收一室模型，其主要动力学参数为：一级吸收速度常数（K_a）1.915h^-1，一级消除速度常数（K）0.099h^-1，表观分布容积（V）2.600L／kg，药时曲线下面积（AUC）123.446mg．h/L，生物利用度（F）80.536％，达峰时间(t_max)2.5h，峰浓度(C_max)10.720μg／ml。根据鸡单剂量药物代谢动力学参数设计多剂量给药方案，给药间隔（τ）为24h，其先导剂量为34.484 mg／Kg．b．w，维持剂量为30 mg／Kg．b．W，稳态平均血药浓度可至4.275μg／ml。多剂量（30mg／Kg．b．w，每日一次，连续5天）口服替硝哗后检测其在组织中的残留。于末次给药后12、24、48、替硝哇在鸡体内的药物动力学和残留研究72h颈静脉放血致死，取肝脏、肌肉、肾脏、脂肪，一20℃避光保存。匀浆后用提取液二氯甲烷:甲醇（98:Zv/v）提取，50⁵5℃水浴下氮气吹干后检测。测定时，室温下解冻，匀浆、提取、HPLC分析。替硝哇在鸡组织中的最低检测限为0.025 pg/g，组织中替硝哇浓度在0.05、0.5、8pg/g时，日内、日l’ed变异系数分别(5%和(l既（n二3），回收率在72.0一96.08%之间，其平均回收率为85.044%。肌肉中替硝哇含量最高，12h时为1.1一4士0.045 pg/g，脂肪其次为0.552士0.0一8 pg/g，肾脏再其次为0.262士0.008 pg/g，肝脏中最低，为0.160士0.006“g/g;24h后，仅肌肉中可检测出，为0.237士0.008协g/g，其它组织均检测不出。 结果表明，反相高效液相色谱法适用于替硝哇在鸡体内的药物动力学和残留的研究。替硝哇在鸡体内吸收快，分布广，半衰期较短，生物利用度高。依照给药方案投药，稳态平均血药浓度高，可达到有效治疗浓度.组织中残留量从低至高依次为肝<肾<脂肪<肌肉，休药期建议为5天.更多还原

【Abstract】 The studies on the Pharmacokinetics of Tinidazole (30mg/kg.b.w.) in 20 chickens after single dose of intravenous and oral administration, and on the residues of Tinidazole (30mg/kg.b.w. oral administration, five days) in tissues are reported in this paper. Plasma samples were collected from brachial vein at every different interval after administration. Tinidazole in the plasma was extracted by dichloromethane: methanol(98:2 v/v) ,and evaporated to dryness at 50-5 5 water bath. The contents were determined by reversed-phase high performance liquid chromatography. Tinidazole was separated on Spectrasystem HPLC instrument using YWG-C 18 column (250 4.6mm, 10 u m),the mobile phase consisted of a degassed mixture methandol:20% acetonitrile: water (25:25:50 v/v), the range of 0.125~64.0 g/ml (r=0.9998). The plasma calibration curve was linear in the range of 0.2~51.2 g/ml (r=0.9989) ,the average recovery was >90%,the inter-day coefficient of variance was <5%(n=3),and intra-day coefficient of variance was<10%.The single dose intravenous and oral administrations concentration-time data were analyzed by pharmacokinetic compartment analysis soft (PKANALYST). The procession after intravenous was fit the two-compartment open model, and its main pharmacokinetic parameters were followed :t1/2, 0.279h;t]/2u 4.705h; Vc 0.857L/kg; Vdss 1.293IAg; Clb 0.206L/kg.h; AUC 153.280 mg.h/L. Theprocession after oral administration fit one compartment model, and its main pharmacokinetic parameters of Tinidazole in chickens were as follows: ka 1.915h’’;k 0.099hf’; V 2.600L/kg; Clb 0.259L/kg.h ; tl/27.173h; AUC 123.446 mg.h/L;F 80.536% ;Tmax 2. 5h;Cmax 10. 720 g/ml. According to the parameters of single dose administration, the administration scheme was followed :Dosing interval 24h;Priming dose 34.484mg/kg;Maintenance dose 30mg/kg;Average steady state concentration 4.275mg/kg.Residues were determined at different interval of 12,24,48,72h after continuous oral administrations. Then collect the samples of livers, muscles, kidneys, and fats after killing every group of the chickens. The samples were determined at the conditions, which was as the same as that of plasma. At 12h, Tinidazole in the muscles is higher than any other tissues then in fats and kidneys, and the livers are the lowest. Tinidazole in muscles could be determined at 72 hours, and could not be detected in other three kinds of tissues after 24 hours. Then suggested that the withdrawal time of Tinidazole should be 5 days.更多还原