Sample preparation and analytical determination of triazole antifungal agents in biological matrices: From conventional workflows to clinical monitoring.

Reliable analytical determination of triazole antifungal agents is essential for therapeutic drug monitoring because of large interindividual pharmacokinetic variability, variable protein binding and clinically important drug interactions. This narrative review evaluates studies published from 2010 onward on fluconazole, itraconazole, hydroxyitraconazole, voriconazole, voriconazole N-oxide, posaconazole and isavuconazole in biological matrices. Across plasma, serum and low-volume matrices, protein precipitation provides rapid preparation for many routine assays, whereas liquid-liquid extraction, microextraction and solid-phase formats offer greater cleanup or enrichment when matrix interference or sensitivity is limiting. Liquid chromatography with ultraviolet or fluorescence detection remains accessible and effective for focused therapeutic drug monitoring when chromatographic resolution is adequate; liquid chromatography-mass spectrometry provides higher molecular selectivity for multiplex measurement of parent drugs and metabolites. Microsampling, online preparation, direct mass spectrometry and selective sorbents can reduce sampling or handling burdens, but their value depends on agreement with validated reference procedures. Method selection should therefore be governed by matrix fitness, the explicitly defined recovery metric, clinically relevant quantification limits, throughput, traceability and turnaround time rather than sensitivity or novelty alone.