UPLC-QTRAP-MS/MS法同时测定大鼠血浆中洛伐他汀和活性代谢产物洛伐他汀酸的浓度及其药动学研究

Simultaneous quantitation of lovastatin and an active metabolite in Rat Plasma by UPLC-QTRAP-MS/MS and its application in the pharmacokinetic

关键词:  洛伐他汀  洛伐他汀酸  超高效液相三重四级杆线型离子阱串联质谱  药动学

Key words:  lovastatin(monacolin K)  lovastatin acid  UPLC-QTRAP-MS/MS  pharmacokinetic

摘要:

目的 建立测定大鼠血浆中洛伐他汀（lovastatin，monacolin K，MK）及其活性代谢产物洛伐他汀酸（monacolin K acid，MKA）浓度的超高效液相三重四级杆线型离子阱串联质谱（UPLC-QTRAP-MS/MS）检测方法，并将其应用于药动学研究。方法 采用乙酸乙酯萃取血浆样品，以辛伐他汀为内标，采用Agilent ZORBAX C₁₈（2.1 mm×50 mm，1.8 μm）为色谱柱，以乙腈-0.1%甲酸为流动相，梯度洗脱流速为0.4 mL·min^-1，柱温为40 ℃。以正离子多反应离子监测模式，用于定量分析的离子对分别为m/z 405.1^®225.1（MK），m/z 423.2^®199.2（MKA），m/z 419.2^®199.1（辛伐他汀）。结果 MK和MKA的线性范围分别为0.08~80.0 ng·mL^-1和1.60~1 600.0 ng·mL^-1，其定量下限分别为0.08，1.60 ng·mL^-1；MK和MKA的日内和日间精密度均<9.0%，准确度在-5.18%~6.83%内；MK和MKA的提取回收率均≥72.26%，RSD均≤10.83%；MK和MKA的基质效应在91.11%~105.73%，RSD均≤7.46%；MK和MKA的C_max分别为（136.22±30.25）ng·mL^-1和（212.57±33.92）ng·mL^-1，T_max分别为（1.58±0.11）h和（2.15±0.26）h，t_1/2分别为（35.42±12.67）h和（17.86±6.15）h，AUC_0-24分别为（279.92±44.18）ng·h·mL^-1和（390.34±20.15）ng·h·mL^-1。结论 该方法快速、灵敏、准确，可用于MK和MKA在大鼠体内的药动学研究。

Abstract:

OBJECTIVE To develop an ultrahigh-pressure liquid chromatography triple-quadrupole linear ion-trap tandem mass spectrometry (UPLC-QTRAP-MS/MS) method for the pharmacokinetic study of lovastatin and its active metabolite (lovastatin acid) in rat plasma. METHODS Plasma samples were extracted by liquid-liquid extraction with ethylacetate, and simvastatin was used as the internal standard (IS). The chromatographic separation was carried out on an Agilent ZORBAX C₁₈(2.1 mm×50 mm, 1.8 μm) column with a gradient mobile phase consisting of acetonitrile and 0.1% formic acid. The flow rate was set at 0.4 mL·min^-1 and the column temperature was 40℃. The detection was performed on positive electrosprayion (ESI⁺) in the multiple reaction monitoring (MRM) mode with transitions of m/z 405.1^®225.1, m/z 423.2^®199.2 and m/z 419.2^®199.1 for lovastatin, lovastatin acid and simvastatin, respectively. RESULTS The method was arranged from 0.08-80.0 ng·mL^-1 and 1.60-1 600.0 ng·mL^-1 for lovastatin and lovastatin acid, respectively. The lower limits of quantification for lovastatin and lovastatin acid were defined as 0.08 ng·mL^-1 and 1.60 ng·mL^-1, respectively. The intra-day and inter-day precision values obtained were <9.0% and the accuracy was between -5.18% and 6.83% for each analyte. The extraction recoveries of their five concentrations for lovastatin and lovastatin acid were all ≥ 72.26%, and the RSD of the extraction recoveries were ≤ 10.83%. The matrix effects ranged from 91.11% to 105.73% and RSD were ≤ 7.46%. The maximum plasma concentrations (C_max) were (136.22±30.25)ng·mL^-1 and (212.57±33.92)ng·mL^-1; the time to maximum plasma concentration (T_max) were (1.58±0.11)h and (2.15±0.26)h; the half-life (t_1/2) were (35.42±12.67)h and (17.86±6.15)h and the areas under the concentration time curves (AUC_0-24h) were (279.92±44.18)ng·h·mL^-1 and (390.34±20.15)ng·h·mL^-1 for lovastatin and lovastatin acid, respectively. CONCLUSION The method is rapid, sensitive and accurate, and it may be applied to the pharmacokinetic study of lovastatin and lovastatin acid in rat plasma.