Abstract
A direct plasma injection liquid chromatographic method has been developed for the determination of a new triazole antifungal agent, voriconazole, using an internal surface reversed phase column. Therapeutic drug monitoring of voriconazole is relevant for patient management, especially in the case of drug–drug interaction. The method is easy to perform and requires 10 µL of a plasma sample. The chromatographic run time is less than 9 min using a mobile phase of 17:83 v/v acetonitrile–potassium dihydrogen phosphate buffer, 100 mm, pH 6.0 and UV detection at 255 nm. The flow rate was 1 µL/min. A linear response was observed over the concentration range 0.5–10 µg/mL (r^2^ = 0.977). A good accuracy (bias ≤ 7.5%) was achieved for all quality controls, with intra‐day and inter‐day variation coefficients inferior to 6.7%. The lower limit of quantitation was 0.2 µg/mL, without interference of endogenous components. The stability of voriconazole in plasma stored at different temperatures was checked. Finally, the possibility of direct injection of plasma samples into the column permits a reduction in reagent consumption and in analytical steps, and hence in analytical error. Copyright © 2004 John Wiley & Sons, Ltd.