猪肌肉注射多拉菌素的药物动力学研究

Pathologic Study and Bacterial Diagnose of Yak Pneumoni

对多拉菌素在猪体内的肌肉注射药物动力学进行了研究。长白×杜洛克杂交猪5头,临床健康,体重36kg^50kg。以300μg/kg体重剂量通过肌肉注射给药,血浆样品经乙腈处理后过18C富集柱,用甲醇提取多拉菌素并进行衍生化反应,以反向HPLC测定血清中的药物浓度,药物动力学参数用MCPKP程序进行处理。结果表明,猪肌肉注射多拉菌素后,血浆药物浓度可测至25d,药物浓度-时间曲线符合二室开放模型。主要药物动力学参数为,t1/2α0.056d±0.022d,t1/2β3.20d±1.34d,AUC223.51μg/(L.d)±65.20μg/(L.d),CMAX28.99μg/L±10.69μg/L,Tp1.24d±0.87d。结果显示,多拉菌素在猪体内具有吸收分布迅速、体内分布容积大、消除缓慢和生物利用度相对较高的特点,并表现为显著的长效性。研究结果对认识多拉菌素在猪体内的动力学特征和指导临床用药具有重要意义。

The plasma pharmacokinetics of doramectin （DRM） after intramuscular （i. m. ） administration at a single dose of 300 g/kg b.w. were determinined in pigs. Five crossbreed pigs, clinical healthy, weighing 36 kg-50 kg were selected for study. Pigs were treated with 300 g/ kg DRM with i.m. injection, blood samples were collected from jugular vein at different time and the separated plasma were derivatized after solid phase extraction and analysed by high performance liquid chromatography （HPLC）. Pharmacokinetics parameters were calculated by a computerized kinetic program MCPKP. The results showed that the drug concentration-time data of DRM with i.m. administration accorded with two compartment open model in pig. The main pharmacokinetic parameters were t1/2α 0．056d±0．022d，t1／2β 3．20d±1．34d，AUC 223．51μg／（L·d）±65．20μg／（L·d），CMAX 28．99μg／L±10．69μg／L，Tp1．24d±0．87d. It indicated that DRM was absorbed and distributed rapidly, eliminated slowly and showed large volume of distribution and high bioavailability in pig with i. m. administration. Therefore, the results are helpful for understanding the pharmacokinetics characteristics and correct using of DRM in pig in clinic.