Chae Jung-woo, Baek Hyun-moon, Kim Sang Kyum, Kang Ho-il, Kwon Kwang-il
College of Pharmacy, Chungnam National University, Daejeon, Korea.
Biomed Chromatogr. 2013 Aug;27(8):953-5. doi: 10.1002/bmc.2895. Epub 2013 Mar 21.
The major metabolite of duloxetine is a glucuronide conjugate of 4-hydroxy duloxetine (4-HD). However, interestingly, there have been no reports determining concentrations of 4-HD and no fully validated method has been established for measuring duloxetine and 4-HD in rat plasma. We developed a method for the simultaneous quantification of duloxetine and its metabolite in rat plasma using high-performance liquid chromatography tandem mass spectrometry. Duloxetine and 4-HD were analyzed on a reverse-phase C18 analytical column after protein precipitation of the plasma sample with methanol, using carbamazepine as an internal standard. The isocratic mobile phase of 5 mm ammonium acetate-methanol (4:6, v/v) was eluted at 0.4 mL/min. Quantification was performed on a triple-quadrupole mass spectrometer using electrospray ionization, and the ion transition monitored in selective reaction monitoring mode. The coefficient of variation for assay precision was <18.0%, and the accuracy was 84.0-118.0%. This method was successfully used to measure the concentrations of duloxetine and its metabolite in plasma following the oral administration of a single 40 mg/kg dose in rats.
度洛西汀的主要代谢产物是4-羟基度洛西汀（4-HD）的葡萄糖醛酸结合物。然而，有趣的是，尚无关于测定4-HD浓度的报道，也没有建立用于测定大鼠血浆中度洛西汀和4-HD的完全验证的方法。我们开发了一种使用高效液相色谱串联质谱法同时定量大鼠血浆中度洛西汀及其代谢产物的方法。血浆样品用甲醇进行蛋白沉淀后，在反相C18分析柱上分析度洛西汀和4-HD，使用卡马西平作为内标。以5 mM醋酸铵-甲醇（4:6，v/v）作为等度流动相，以0.4 mL/min的流速洗脱。在三重四极杆质谱仪上使用电喷雾电离进行定量，并在选择反应监测模式下监测离子跃迁。测定精密度的变异系数<18.0%，准确度为84.0-118.0%。该方法成功用于测定大鼠口服单次40 mg/kg剂量后血浆中度洛西汀及其代谢产物的浓度。
