LC-MS/MS法测定Beagle犬血浆中美托拉宗的浓度

Determination of metolazone in Beagle dog plasma by LC-MS/MS

目的建立Beagle犬血浆中美托拉宗浓度的液相色谱-串联质谱(LC-MS/MS)测定方法。方法色谱柱:依利特C18柱(150 mm×4.6 mm,5μm),流动相:乙腈-5 mmol.L-1醋酸铵-甲酸(体积比为60.00:40.00:0.05),血浆样品采用乙腈沉淀蛋白法处理,以多反应监测(multiple reaction moni-toring,MRM)扫描方式检测,测定Beagle犬口服美托拉宗后血浆中药物浓度。结果血浆中美托拉宗质量浓度在0.5～200.0μg.L-1内线性关系良好,r=0.995 2;日内和日间精密度RSD≤12.2%;美托拉宗的平均提取回收率为66.0%～72.9%,基质效应符合有关规定,美托拉宗在Beagle犬血浆中主要药物动力学参数:t1/2为(7.6±2.1)h,ρmax为(144.2±29.5)μg.L-1,AUC0-∞为(2081.5±516.0)μg.h.L-1。结论该方法适用于美托拉宗在Beagle犬体内的药物动力学研究。

Objective To develop a simple, rapid and sensitive liquid chromatography-tandem mass spectrometry（ LC-MS/MS） method for the determination of metolazone in dog plasma. Methods Protein precipitation was used for the sample pretreatment with a plasma volume of 100 μL. The chromatographic separation was carried out on an Elite C18 analytical column （150 mm × 4.6 mm, 5 mm） at a ＆#64258;ow rate of 0.5 mL min-1 and the mobile phase was composed of acetonitrile-5 mmol·L-1 ammonium acetate-formic acid （V：V：V=60.00：40.00：0.05）. Detection was carried out by multiple reaction monitoring. Results The method was linear over the range of 0.5-200.0 μg·L-1 and the lower limit of quantification （LLOQ） was 0.5 μg·L-1. The intra- and inter-day precision was within 12.2% in terms of relative standard deviation （RSD%）. The average recoveries were between 66.0-72.9%, the matrix effects were between 55.6–62.1%. Main pharmacokinetic parameters were as follows： t1/2 （7.6 ± 2.1） h, ρmax （144.2 ± 29.5） μg·L-1, AUC0-￥ （2 081.5 ±516.0） μg·h·L-1, respectively. Conclusions This simple and sensitive LC-MS/MS method was successfully applied to pharmacokinetic studies of metolazone in Beagle dogs after an oral dose of 5.0 mg metolazone.