Background and importance The incidence of invasive fungal infections has increased significantly. Triazoles are the antifungals of choice for pulmonary aspergillosis, but they have a high intra- and interindividual variability in pharmacokinetics and are associated with a large number of interactions, thus requiring analytical techniques that allow therapeutic drug monitoring to ensure the effectiveness and safety of these drugs.

Aim and objectives The aim of this study was the development and validation of a high-performance liquid chromatography (HPLC) method for measuring voriconazole, isavuconazole and posaconazole in human plasma using tioconazole as an internal standard.

Material and methods The system consisted of an Agilent 1260 Infinity chromatograph with an ultraviolet diode array detector (UV-DAD). The column used was a Kinetex F5 4.6 ×150 mm, 5 µm (Phenomenex, USA). The method was validated according to the Food and Drug Administration (FDA) bioanalytical method validation guidance. The analysis run time for all drugs was 7.5 min. The chromatographic conditions are shown in Table 1. To process the samples were taken 100 µL of internal standard, 200 µL of plasma and 300 µL of acetonitrile. Then, they were homogenised for 30 s and centrifuged at 15 000 g for 5 min.

Results The results are shown in Table 2.

Conclusion and relevance A method has been validated for the determination of triazoles by HPLC in human plasma that will allow therapeutic drug monitoring to be performed in target patients.

References and/or acknowledgements 1. Laverdiere M, Bow EJ, Rotstein C, Autmizguine J, Broady R, Garber G, et al. Therapeutic drug monitoring for triazoles: a needs assessment review and recommendations from a Canadian perspective. Can J Infect Dis Med Microbiol 2014;25(6):327–343.

Food and Drug Administration (FDA). Guidance for Industry, Bioanalytical Method Validation; 2018. https://www.fda.gov/media/70858/download

Conflict of interest No conflict of interest