A rapid HPLC method with fluorometric detection for determination of plasma itraconazole and hydroxy‐itraconazole concentrations in cystic fibrosis children with allergic bronchopulmonary aspergillosis

Abstract

The development and validation of a simple, rapid and selective high-performance liquid chromatography (HPLC) method is described for the quantitation of itraconazole and hydroxy-itraconazole in 100 microL of plasma from a paediatric population. The mobile phase of methanol (75% v/v) and water (25% v/v) was pumped at 1 mL/min through a C18 Symmetry (3.9 mm i.d. x 150 mm) cartridge. Using a protein-precipitation method, 100 microL internal standard (IS) solution (R051012, 555 microg/L in acetonitrile) were added to 100 microL of plasma followed by 10 microL zinc sulphate solution (20% w/v). Itraconazole, hydroxy-itraconazole and IS eluted at 4.7, 8.3 and 12.5 min, respectively and were detected fluorometrically at 250 nm (excitation) and 380 nm (emission). Recoveries were 87.1-96.7%. Calibrations in drug-free plasma were linear (r2 > 0.99) from 50 to 2000 microg/L, using 1/c2 (c = concentration) weighting. Intraday and interday imprecision (CV%) was 4.8-17.3 and 6.3-16.6% for itraconazole, and 4.6-17.9 and 7.02-18.4% for hydroxy-itraconazole. Inaccuracy was -7.1 to -14.7% for itraconazole and -0.1 to -9.7% for hydroxy-itraconazole. The clinical application of this method was demonstrated by measurement of itraconazole and hydroxy-itraconazole in plasma samples drawn from paediatric cystic fibrosis patients, who were prescribed itraconazole for treatment of allergic bronchopulmonary aspergillosis.

Development, Validation, and Routine Application of a High-Performance Liquid Chromatography Method Coupled with a Single Mass Detector for Quantification of Itraconazole, Voriconazole, and Posaconazole in Human Plasma

“…Drug interactions are often related to subtherapeutic concentrations caused by the specific metabolic pathway of triazoles. In particular, ITC is both an inhibitor and a substrate of cytochrome P450 3A4 (CYP3A4) (47) and of the P-glycoprotein transporter system (23,32), and PSC is an inhibitor of CYP3A4 and is metabolized by glucuronization (40,47). VRC is a substrate and inhibitor of CYP2C19, CYP2C8/9, and CYP3A4 (23,47).…”

“…Antifungal therapeutic drug monitoring (TDM) could be an important tool in clinical practice if compliance is poor, the therapeutic window is narrow, or drug interactions and toxicity are common adverse effects. Therefore, quantification of drug in plasma samples is an important issue in clinical practice to improve efficacy and to decrease toxicity.Many methods to individually quantify ITZ (6,7,9,17,18,26,[31][32][33][34]37,45,46), PSC (8,35,39), and VRC (11,20,24,25,28,29,36,38) in human plasma have been published. Only one method described the quantification of the three triazoles plus fluconazole, ITC metabolite, and ketokonazole in human plasma using a solid-phase extraction procedure.…”

Formulation and delivery of itraconazole to the brain using a nanolipid carrier system

“…25 The HPLC system (Agilent 1260 HPLC series) used was equipped with a sample injection port fitted with a 100 µL sample loop and a fluorescence detector. The analytical column used was the Phenomenex C-18 analytical column (5 µm, 4.6 × 150 mm).…”

Clinical Significance of Measuring the Blood Concentration of Itraconazole Oral Solution in the Field of Hematology

“…15) We quantified ITCZ in plasma by modifying the method described previously. To remove proteins, 10 ml of 20 w/v% zinc sulfate solution and 100 ml of 500 ng/ml acetonitrile solution, as an internal standard (R051012), were added to 100 ml of plasma.…”