Pharmacokinetic study and metabolite identification of Colistin sulfate in rats

Table 1：Drug concentration of Colistin in plasma and tissue of rats.After intravenous injection of colistin (6 mg/kg), distribution peaked in the kidney at (125.8 ± 22.55) μg/mL, indicating it as a primary biotransformation site. Liver and lung levels exceeded plasma, while heart and spleen levels were low. No colistin was detected in the intestine.
Table 2：Residual percentage of Colistin at different time points in the in vitro incubation model (Mean ± SD，n=3).The t1/2 and CLint values in liver, kidney, and lung models varied, with lung showing the slowest elimination. Microsomes exhibited slower elimination than tissue homogenates, and kidney and liver microsomes had similar t1/2 and CLint values despite differences in degradation.

表 1：鼠血浆和组织中硫酸粘菌素浓度。硫酸粘菌素（6 mg/kg）静脉注射后，分布峰值出现在肾脏，达到（125.8 ± 22.55）μg/mL，表明肾脏是其主要的生物转化场所。肝脏和肺部的浓度超过血浆水平，而心脏和脾脏的浓度较低。肠道中未检测到硫酸粘菌素。

表 2：体外孵育模型中不同时间点硫酸粘菌素残留百分比（均值 ± 标准差，n=3）。肝脏、肾脏和肺部的半衰期（t1/2）和表观分布容积（CLint）值存在差异，其中肺部表现出最慢的消除速率。与组织匀浆相比，微粒体表现出更慢的消除速率，尽管在降解方面存在差异，肾脏和肝脏的微粒体具有相似的半衰期和表观分布容积值。