替米考星在绵羊体内的药代动力学研究

5只健康小尾寒羊，采用静脉和皮下注射2种途径以替米考星10mg/kg体重剂量给药，进行体内药代动力学研究。动物给药后在96h内分点采血，血浆样品处理采用甲醇沉淀，离心去蛋白，调节pH值并用氯仿提取替米考星；样品测定采用苯基柱，以反向HPLC测定绵羊血清中的替米考星浓度。结果表明，绵羊静注和皮下注射替米考星的药时数据均符合二室开放模型，替米考星皮下注射和静脉给药在羊体内具有吸收和分布较迅速，消除缓慢，体内分布容积大，生物利用度较高的特点。结果对了解替米考星在绵羊体内的药动学特征以及指导临床正确用药具有重要意义。

Pharmacokinetics of Tilmicosin in Sheep

Tilmicosin was administered to 5 healthy Xiaoweihan sheep intravenously(i.v.) and subcutaneously(s.c.) at a single dose of 10 mg/kg b.w. to determine its concentration in blood and its kinetic behaviour. Blood samples were collected from jugular vein at different time points during 96 hours after administration, then treated with methanol and centrifuged to removal proteins. Tilmicosin was extracted by chloroform following the pH value modified with NaOH solution and analyzed with a reversed-phase HPLC with phenyl column. The tilmicosin concentration-time data of both i.v. and s.c. administration were analyzed with a two compartment open model. It resulted that tilmicosin was rapidly absorbed and distributed and slowly eliminated after single i.v. and s.c. administration in healthy sheep. The drug exhibited large volume of distribution and high bioavailability in sheep. Therefore, the results are helpful for understanding the pharmacokinetic characteristics and rational application in clinic of tilmicosin in sheep.