正负离子切换液相色谱-串联质谱法同时测定人血浆中头孢他啶和他唑巴坦

目的: 建立灵敏、专属的液相色谱-串联质谱法同时测定人血浆中头孢他啶和他唑巴坦,并用于临床药代动力学研究。方法: 血浆样品经乙腈沉淀蛋白后,以乙腈-5 mmol·L^-1醋酸铵-甲酸(20∶80∶0.16,v/v/v)为流动相,使用Venusil ASB-C₁₈柱(150 mm×4.6 mm,5 μm)分离。采用电喷雾电离源,多反应监测模式(MRM),以正负离子切换同时测定头孢他啶和他唑巴坦,切换时间在进样后3.8 min。头孢他啶采用正离子检测,用于定量的离子反应分别为m/z 547→468(头孢他啶),m/z 364→208(内标头孢羟氨苄),头孢他啶和内标头孢羟氨苄的保留时间分别为3.0 min和2.8 min;他唑巴坦采用负离子检测,用于定量的离子反应分别为m/z 299→138(他唑巴坦),m/z 232→140(内标舒巴坦),他唑巴坦和内标舒巴坦的保留时间分别为4.4 min和4.9 min。结果: 头孢他啶和他唑巴坦的线性范围分别为0.250~250 μg·mL^-1和0.0250~25.0 μg·mL^-1,日内、日间精密度(RSD)均小于10.8%,准确度(RE)在-7.6%~2.1%之间。本法被成功应用于健康受试者静脉滴注不同剂量头孢他啶/他唑巴坦钠(6∶1)注射液(头孢他啶/他唑巴坦含量分别为1 g/0.167 g,2 g/0.333 g,4 g/0.667 g)的药动学研究。结论: 该方法专属性强,灵敏度高,操作简便,适用于注射用头孢他啶/他唑巴坦临床药代动力学研究。

Objective: To develop a sensitive and specific liquid chromatographic-tandem mass spectrometric(LC-MS/MS) method for simultaneous determination of ceftazidime and tazobactam in human plasma and applied to the pharmacokinetic study. Methods: The plasma sample was extracted with acetonitrile, then separated on a Venusil ASB-C₁₈ column(150 mm×4.6 mm, 5 μm) using acetonitrile-5 mmol·L^-1 ammonium acetate-formic acid (20∶80∶0.16,v/v/v) as mobile phase. Ceftazidime was ionized under positive ESI condition, while tazobactam required negative ESI condition in order to improve sensitivity. The witch time from positive ion to negative ion was at 3.8 min. The retention times for ceftazidime and cefadroxil(internal standard) were 3.0 min and 2.8 min, respectively. The retention times for tazobactam and sulbactam(internal standard) were 4.4 min and 4.9 min, respectively. Multiple reaction monitoring (MRM) using the precursor to product ion of m/z 547→468, m/z 299→138, m/z 364→208 and m/z 232→140 were performed to quantify ceftazidime, tazobactam, internal standard cefadroxil and sulbactam, respectively. Results: The linear calibration curves for ceftazidime and tazobactam were obtained in the concentration range of 0.250-250 μg·mL^-1 and 0.0250-25.0 μg·mL^-1. Intra-and inter-day relative standard deviation(RSD) for ceftazidime and tazobactam over the entire concentration across three validation runs was both less than 10.8%, and relative error(RE) ranged from-7.6% to 2.1%. The method was successfully applied to a pharmacokinetic study of intravenous drip of three doses of ceftazidime/tazobactam sodium (containing ceftazidime/tazobactam at 1 g/0.167 g, 2 g/0.333 g, 4 g/0.667 g) in healthy volunteers. Conclusion: The method herein described is effective, convenient and suitable for the clinical pharmacokinetic study of ceftazidime/tazobactam.