Journal of Clinical & Experimental Pharmacology

Abstract

A New HPLC Validated Method for Therapeutic Monitoring Of Triazoles in Human Plasma: First Results in Leukaemic Patients

Silvia De Francia, Paolo Cardalana MLT, Elisa Pirro P, Francesca Maria Piccione, Giuliana Abbadessa, Vitina Carriero, Antonia Rotolo, Marco De Gobbi, Angelo Guerrasio, Silvia Racca and Giuseppe Reimondo

Abstract Therapeutic drug monitoring of triazoles is widely used in clinical practice to optimize therapy, especially in those patients who need antifungal treatment as co-medications. Here it is described development and validation of a new chromatographic method in order to quantify voriconazole and posaconazole in human plasma by ultraviolet detection. After liquid extraction of analytes from plasma using acetonitrile, samples are evaporated to dryness and then reconstituted in mobile phase for chromatographic separation. Analysis is achieved on C18 reverse phase column and eluate is monitored at 250 nm. Mobile phase consisted of 35% water, 15% methanol, 50% acetonitrile. Flavone was used as internal standard; retention times (minutes) were, respectively, for voriconazole 3.9, posaconazole 7.9, flavone 7.1. Accuracy and variability were assayed by inter- and intra-day validation, conducted on three separate days. Methodology was used for the analysis of plasma samples of acute myeloid leukaemia patients in therapy with voriconazole or posaconazole for treatment of fungal infections, in order to perform therapeutic monitoring of antifungal drugs levels. Mean inter- and intra-day accuracy and variability were acceptable for both compounds; thus, method developed resulted linear in the range 0.125–8 μg/mL. Limits of quantification and limits of detection for voriconazole and posaconazole are, respectively, 0.100 and 0.050 μg/mL, and 0.030 and 0.020 μg/mL. It has been observed that voriconazole and posaconazole circulating levels achieved in patients are on average below the therapeutic range defined in literature. In conclusion, method developed and validated in order to quantify voriconazole and posaconazole in human plasma is accurate and precise; it is easily applicable and reproducible, and, therefore, it could be an useful tool in clinical routine to better manage patients in case of multi-therapy approach.