Development and validation of a UPLC-MS/MS method for quantification of doxofylline and its metabolites in human plasma

• Published in: Journal of pharmaceutical and biomedical analysis 2019-09, Vol.174, p.220-225
• Main Authors: Fang, Li-Na, Mao, Ming-Qing, Zhao, Xiao-Hua, Yang, Ling, Jia, Hui, Xia, Shu-Yue
• Format: Article
• Language: English
• Subjects: Adult; Calibration; Chromatography, High Pressure Liquid - methods; Doxofylline; Female; Healthy Volunteers; Humans; Infusions, Intravenous; Male; Metabolites; Pharmacokinetics; Reproducibility of Results; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry - methods; Theophylline - analogs & derivatives; Theophylline - blood; Theophylline - pharmacokinetics; UPLC-MS/MS
• ISSN: 0731-7085; 1873-264X
• DOI: 10.1016/j.jpba.2019.05.039

•First report of the determination of doxofylline and its metabolites in plasma.•Good accuracy, precision and recovery was achieved by protein precipitation.•The method was successfully applied to a pharmacokinetic study in human.•Pharmacokinetic parameters of the two main metabolites of doxofylline in healthy volunteers are first reported. A sensitive and specific ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for simultaneous determination of doxofylline and its two metabolites in human plasma. After protein precipitation with methanol, the chromatographic separation was carried out on an ACQUITY UPLC HSS T3 column, with acetonitrile and 0.1% formic acid in water as mobile phase at a flow rate of 0.30 mL·min−1. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via electrospray ionization (ESI) source, with target quantitative ion pairs of m/z 267.0→181.1 for doxofylline, 239.0→181.1 for theophylline-7-acetic acid and 225.1→181.1 for etofylline. The calibration curve was linear over the range of 2–3000 ng·mL−1 (r > 0.99). The LLOQ was evaluated to be 2 ng·mL−1. The method described herein allowed simultaneous determination of the three analytes for the first time and was successfully applied to the pharmacokinetic study of doxofylline and its metabolites after intravenous administration in healthy volunteers.