Abstract
A rapid and simple high-performance liquid chromatography (HPLC) assay was developed for the simultaneous determination of three triazole antifungals (voriconazole, posaconazole, and itraconazole and the metabolite of itraconazole, hydroxyitraconazole) in human plasma. Sample preparation involved a simple one-step protein precipitation with 1.0 M perchloric acid and methanol. After centrifugation, the supernatant was injected directly into the HPLC system. Voriconazole, posaconazole, itraconazole, its metabolite hydroxyitraconazole, and the internal standard naproxen were resolved on a C6-phenyl column using gradient elution of 0.01 M phosphate buffer, pH 3.5, and acetonitrile and detected with UV detection at 262 nm. Standard curves were linear over the concentration range of 0.05 to 10 mg/liter (r2 > 0.99). Bias was <8.0% from 0.05 to 10 mg/liter, intra- and interday coefficients of variation (imprecision) were <10%, and the limit of quantification was 0.05 mg/liter.