LC-MS/MS法测定血浆中米非司酮及低剂量人体药代动力学研究

目的: 建立LC-MS/MS法测定人血浆中米非司酮浓度,并对口服10 mg米非司酮片后的药代动力学进行研究. 方法: 血浆样品以他达那非为内标,经乙腈沉淀蛋白后进行LC-MS/MS分析.采用高效液相色谱分离系统,色谱柱为SunFire C₁₈柱(150 mm×2.1 mm,5 μm),流动相为10 mmoL·L^-1醋酸铵溶液-乙腈-甲酸(20: 80: 0.2);采用质谱检测系统,ESI离子源,正离子模式,多反应监测(MRM)方式监测m/z 430→m/z372(米非司酮)和m/z 390→m/z268(内标他达那非). 结果: 米非司酮质量浓度在1.0~1 000.0 ng·mL^-1范围内与色谱响应相关性良好,定量下限为1.0 ng·mL^-1.批内及批间精密度RSD均小于9%,准确度在91.0%~107.6%.20名受试者单次服用10 mg米非司酮片后AUC_0-96h为(4 198.2±1 792.8)ng·mL^-1·h,AUC_0-∞为(4 384.2±1 880.1)ng·mL^-1·h,C_max为(476.4±223.1)ng·mL^-1,t_max为(1.04±0.80)h,t_1/2为(20.61±6.50)h,MRT为(21.46±4.32)h,CL为(2.7±1.1)L·h^-1,V_d为(75.9±28.0)L. 结论: 本测定方法灵敏准确,简便易行,适用于服用低剂量米非司酮后血药浓度的测定及其药代动力学研究.研究结果显示米非司酮片口服后吸收较快,1 h左右达峰值;受试者用药后无不良事件发生,安全性较高.

Objective: To develop a sensitive and selective LC-MS/MS method for determination of mifepristone in human plasma and to study its pharmacokinetic feature in healthy volunteers after a single dose of 10 mg mifepristone tablets. Methods: After adding tadalafil as the internal standard(IS),plasma was deproteinized with acetonitrile.The analyte was isocratically eluted on a SunFire C₁₈ column(150 mm×2.1 mm,5 μm)with 10 mmol·L^-1 ammonium acetate solution-acetonitrile-formic acid(20: 80: 0.2)by LC-MS/MS with positive ionization.Ions monitored in the multiple reaction monitoring(MRM)mode were m/z 430→m/z 372 for lipoic acid and m/z390→m/z 268 for tadalafil(IS). Results: The linear range of the standard curve of mifepristone was from 1.0 ng·mL^-1 to 1 000.0 ng·mL^-1.The lower limit of quantification(LLOQ)of lipoic acid was 1.0 ng·mL^-1 and RSD of intra-and inter-batch precision was less than 9%,and the accuracy was between 91.0% -107.6%.Mean pharmacokinetic parameters for mifepristone in 20 volunteers after a single dose of 10 mg mifepristone tablet were as followed:AUC_{0-96 h} (4 198.2±1 792.8)ng·mL^-1·h,AUC_0-∞ (4 384.2±1 880.1)ng·mL^-1·h,C_max (476.4±223.1)ng·mL^-1,t_max (1.04±0.80)h,t_1/2 (20.61±6.50)h,MRT(21.46±4.32)h,CL(2.7±1.1)L·h^-1,V_d (75.9±28.0)L. Conclusion: The established LC-MS/MS method is highly sensitive and accurate,which is suitable for the pharmacokinetic study of mifepristone in human plasma.The absorption is fast after oral administration of mifepristone tablets and the plasma concentration reached the peak in about 1 h.The safety is good as no adverse drug events happened in the study.