LC-MS法测定大鼠血浆中EXH-1626的浓度及其药代动力学研究

Determination of concentration of EXH-1626 in rat' s plasma by LC-MS and its pharmacokinetics

目的建立大鼠血浆中EXH-1626的LC-MS定量分析方法,并运用于大鼠体内EXH-1626的药代动力学研究。方法色谱柱为汉邦ODS C18柱（150 mm×4.6 mm,5μm）,流动相为乙腈-10 mmol/L醋酸铵水溶液（用乙酸调pH至3）70∶30,流速为0.6 mL/min;质谱用ESI离子源及选择性离子监测（SIM）。血浆样品加入内标卡马西平,经蛋白沉淀剂沉淀血浆蛋白,测定EXH-1626的血药浓度,数据经BAPP2.2软件拟合处理,分别考察2个剂量下灌胃和静脉注射给药后,大鼠体内的药代动力学特征。结果血浆中EXH-1626在5~10 000 ng/mL范围内线性关系良好（r=0.999 7）,方法学回收率、精密度、稳定性等均符合要求。大鼠灌胃给药（80 mg/kg）后,其血药浓度-时间过程符合一室模型（W=1）,t1/2为24.14 h、Cmax为222.33 ng/mL、Tmax为5.50 h,当大剂量灌胃给药（250 mg/kg）时,大鼠体内药时曲线呈现多峰曲线,药动学过程呈现明显的非线性特征;大鼠尾静脉注射给药（10和20 mg/kg）后体内药时过程也符合一室模型（W=1）,t1/2分别为2.23和5.48 h、血浆清除率（CL）分别为0.29和0.08 L/（h·kg）。结论 EXH-1626在大鼠体内存在饱和非线性动力学,所建立的方法快速、准确、灵敏度高,适用于EXH-1626血药浓度测定及其非临床药代动力学研究。

Objective To establish a LC-MS method to quantify EXH-1626 in rat plasma and study its pharmacokinetics. Methods The analysis was conducted with a Han Bang ODS C18（150 mm ×4.6 mm,5 μm） column.The mobile phase consisted of acetonitrile and 10 mmol /L ammonium acetate（using acetic acid makes pH to 3）（70∶ 30）,at a flow rate of 0. 6 mL /min. ESI and SIM were used for MS. Using carbamazepine as internal standard,plasma samples were deposited by blood precipitation reagent before sampling. The concentrations of EXH-1626 in rat blood were determined and processed by BAPP2. 2 program. The method was applied to analyze the dynamic process in the body by giving rats i. g. and i. v. two different doses,respectively. Results The linearity of EXH-1626 concentration curve was in a range of 5 ~ 1. 0 × 104ng /mL,r = 0. 999 7,the precision,extraction recovery and stability limit of this method met the requirements of pharmacokinetic study. The mean plasma concentrations of EXH-1626 after i. g. 80mg /kg EXH-1626 in rats could be fitted to a one-compartment model with a weigh of 1. t1 /2was 24. 14 h,Cmaxwas222. 33 ng /mL,and Tmaxwas 5. 50 h. While giving the large dose（250 mg /kg）,it showed multi-peak curve,the pharmacokinetic process had obvious nonlinear characteristic. While after i. v. 10 and 20 mg /kg EXH-1626 in rats,it could be also fitted to a one-compartment model with a weigh of 1. t1 /2were 2. 23 and 5. 48 h,plasma clearances were 0. 29and 0. 08 L /（h·kg）,respectively. Conclusion EXH-1626 exhibits nonlinear pharmacokinetics characteristics in rat.The method is fast,precise and sensitive,and suitable for determination concentration and non-clinical pharmacokinetic study of EXH-1626.