A general and rapid LC-MS/MS method for simultaneous determination of voriconazole, posaconazole, fluconazole, itraconazole and hydroxyitraconazole in IFI patients.

Objective: To establish a rapid and universal quantitative liquid chromatography tandem mass spectrometry (LC-MS/MS) method for measuring the exposure levels of five triazole antifungal drugs in human plasma, including voriconazole, fluconazole, posaconazole, itraconazole, and hydroxyitraconazole.

Methods: A triple quadrupole mass spectrometer operating in positive ionization mode was used to detect the analyte, and multiple reaction monitoring mode was employed to gather data. The mobile phase included 0.05 % formic acid in water (phase A) and acetonitrile (phase B). The analytes were separated on an Agilent EclipsePlusC RRHD column (30 × 50 mm, 1.8 μm) using gradient elution. The flow rate was 0.3 mL/min with the column temperature set at 35 °C. The acetonitrile was used to pretreat the plasma sample, and the itraconazole-D5 and hydroxyitraconazole-D5 were utilized as the internal standards.

Results: The calibration range was from 100 to 10,000 ng/mL for posaconazole, itraconazole, and hydroxyitraconazole, from 200 to 20,000 ng/mL for fluconazole and from 50 to 5000 ng/mL for voriconazole, with linear correlation coefficients more than 0.99 for all regression curves. The intra- and inter-day accuracy and precision of the method were within ±15 %. The mean extraction recovery of all the analytes ranged from 74.32 % to 117.83 %, and the matrix effect was from 72.54 % to 111.2 %. The results of stability fell into the scope of ±15 % deviation.

Conclusion: This newly developed method is sensitive, simple, and robust, and successfully applied in determining triazole antifungal drugs in plasma from 66 IFI patients to provide reference for safe and effective drug administration in clinical practice.