LC-MS/MS法测定Beagle犬血浆中紫杉醇及其药代动力学研究

目的: 建立LC-MS/MS分析方法用于检测Beagle犬血浆中紫杉醇浓度，并研究注射用紫杉醇脂质体的药代动力学。方法: 12只Beagle犬随机分成2组后分别i.v.给予1 mg·kg^-1受试制剂与参比制剂，在不同时间采集血浆样品，采用C₁₈反相色谱柱(250 mm×4.6 mm，5 μm)，流动相为甲醇-0.1%醋酸水溶液(85∶15，v：v)，以多烯紫杉醇为内标，电喷雾离子化(ESI)，正离子扫描模式，多反应离子检测(SRM)，紫杉醇[M+Na⁺] m/z 876.4→591.3，内标多烯紫杉醇[M+Na⁺] m/z 830.4→303.9，应用DAS 2.0药代动力学计算程序计算药代动力学参数。结果: 紫杉醇的检测浓度范围在3~2000 ng·mL^-1呈线性相关(r=0.9980)；定量下限为3 ng·mL^-1；批内和批间变异均小于15.0%。紫杉醇给药后血药浓度-时间曲线符合二室模型，受试药物和参比制剂的主要药代动力学参数t_1/2、C_max、MRT_0-24、AUC_0-24和AUC_0-∞分别为(7.3±2.0)h和(7.2±2.5)h、(796.1±321.8)ng·mL^-1和(1248.0±178.6)ng·mL^-1、(6.2±1.1)h和(5.3±0.8)h、(948.4±100.2)ng·h·mL^-1和(969.7±322.1)ng·h·mL^-1、(1022.1±232.7)ng·h·mL^-1和(1084.0±304.1)ng·h·mL^-1。结论: 本分析方法对血浆中紫杉醇的检测具有专属性，且灵敏、可靠，对上述药代动力学参数以SAS统计软件进行双侧t检验，结果表明给予受试制剂及参比制剂后犬的主要药代动力学参数差异无统计学意义(P>0.05)。

Objective: To establish an LC-MS/MS method for determination of paclitaxel in plasma and to study its pharmacokinetic profile in Beagle dogs.Methods: Twelve Beagle dogs were randomly divided into two groups and then injected test and reference preparations,respectively,through intravenous administration.Plasma samples were collected at different time points.The analyte was separated through a reversed-phase C₁₈ column(250 mm×4.6 mm,5 μm)with a mobile phase of methanol-0.1% acetic acid water solution(85∶15,v/v),and analyzed by electro-spray ionization(ESI)in selected reaction monitoring mode(SRM).The monitoring ions were [M+Na⁺] m/z 876.4→591.3 and [M+Na⁺] m/z 830.4→303.9 for paclitaxel and the internal standard(IS) docetaxel,respectively.After determination of drug concentration in plasma by LC-MS/MS,the pharmacokinetic parameters were calculated using DAS 2.0 software.Results: The calibration curves were linear over the concentration ranging from 3 to 2000 ng·mL^-1 (r=0.9980)with the LLOQ of 3 ng·mL^-1.The within- and between-batch precisions were generally good(<15%).The concentration-time curve for paclitaxel liposome was in accordance with the two-compartment model.The main pharmacokinetic parameters t_1/2,C_max,MRT_0-24,AUC_0-24,and AUC_0-∞ for test and reference preparations were as follows:(7.3±2.0)h,(7.2±2.5)h;(796.1±321.8)ng·mL^-1,(1248.0±178.6)ng·mL^-1;(6.2±1.1)h,(5.3±0.8)h;(948.4±100.2)ng·h·mL^-1,(969.7±322.1)ng·h·mL^-1;(1022.1±232.7)ng·h·mL^-1,(1084.0±304.1)ng·h·mL^-1.Conclusion: The analytical method developed is sensitive,specific,rapid,and reproducible,and it is suitable for pharmacokinetic studies of paclitaxel in Beagle dogs.The two-sided test for pharmacokinetic statistics above with SAS software showed that there were no significant differences(P>0.05)between the test and reference preparation in major pharmacokinetic parameters in Beagle dogs.