HPLC-MS/MS法测定大鼠血浆中麻醉椒苦素的浓度及其药动学研究

目的: 建立大鼠血浆中卡瓦内酯麻醉椒苦素的液相色谱质谱联用定量分析方法,并用于大鼠体内药物动力学研究。 方法: 采用Waters Symmetry Shield C₈(3.0 mm×150 mm,5.0 μm)色谱柱,流动相为乙腈-0.2%甲酸溶液(60: 40,v/v)。三重四极杆质谱仪进行多反应监测(MRM)模式,电喷雾离子源(ESI)正离子检测。生物样品预处理采用乙酸乙酯液-液萃取,考察麻醉椒苦素灌胃给药后,大鼠体内药物动力学特征。 结果: 在大鼠血浆中麻醉椒苦素浓度与峰面积比呈良好线性关系(r=0.9998),线性范围为10~20000 μg·L^-1,定量下限为10 μg·L^-1,样品分析时间为5.5 min。日内、日间精密度(RSD)均小于5.3%,准确度在±10.3%之内。SD大鼠灌胃给药麻醉椒苦素120 mg·kg^-1后,平 均血药峰浓度为8.92 mg·L^-1,血药浓度达峰时间平均为4.00 h。 结论: 所建立的HPLC-MS/MS定量分析方法特异、快速、灵敏,可用于麻醉椒苦素临床前药物动力学研究。

Objective: To establish a high performance liquid chromatography-tandem mass spectrometric method(HPLC-MS/MS)for the determination of methysticin in rat plasma,which was used subsequently to determine the pharmacokinetics of methysticin in rats. Methods: A Waters Symmetry Shield C₈ column(3.0 mm×150 mm,5.0 μm)was used with a mobile phase consisting of acetonitrile-0.2% formic acid(60: 40,v/v).The determination was performed with electrospray ionization(ESI)source in the positive multiple reaction monitoring(MRM)mode by a triple quadrupole tandem mass spectrometer.Rat plasma samples were pretreated with ethyl acetate for liquid-liquid extraction of methysticin.Experiments were conducted to determine the pharmacokinetics of methysticin following a single intragastric dose. Results: A good linearity of methysticin was obtained in the concentration range of 10-20000 μg·L^-1(r=0.9998).The limit of quantification(LOQ)was 10 μg·L^-1.The run time for each sample was 5.5 min.The intra-and inter-day precisions at four quality control(QC)levels were all less than 5.3%.The accuracy of the assay was within ±10.3%.The average maximum concentration of drug(C_max)was 8.92 mg·L^-1 and the time to the maximum concentration(T_max)was 4.00 h after a single intragastric administration of methysticin to SD rats at a dose of 120 mg·kg^-1. Conclusion: A sensitive,rapid and precise LC-MS/MS method is developed and validated for determination of methysticin in rat plasma.The method is proved to be suitable for the preclinical pharmacokinetics of methysticin.