title: 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.
authors.affiliation: School of Pharmacy, The University of Queensland and the Australian Centre for Paediatric Pharmacokinetics, Mater Health Services, Brisbane, Qld, Australia. sredmann@pharmacy.uq.edu.au
authors.forename: Stefanie
authors.initials: S
authors.lastname: Redmann
authors.forename: Bruce G
authors.initials: BG
authors.lastname: Charles
mesh_terms: D000293:Adolescent; D000935:Antifungal Agents / Q000097:blood*; D001229:Aspergillosis, Allergic Bronchopulmonary / Q000097:blood* / Q000188:drug therapy; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003550:Cystic Fibrosis / Q000150:complications*; D005260:Female; D005470:Fluorometry / Q000379:methods; D006801:Humans; D007223:Infant; D017964:Itraconazole / Q000031:analogs & derivatives* / Q000097:blood* / Q000627:therapeutic use; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000935:Antifungal Agents; C084794:hydroxyitraconazole; D017964:Itraconazole