title: Quantification of the 5-lipoxygenase inhibitor zileuton in human plasma using high performance liquid chromatography-tandem mass spectrometry.
abstract: Zileuton is an orally active, selective inhibitor of 5-lipoxygenase, which catalyzes the first step in the conversion of arachadonic acid into leukotrienes. Given the important role of leukotrienes in inflammation and cell signaling, multiple studies have investigated the efficacy of zileuton in the treatment of human disease. Examples of disease targets include asthma, ulcerative colitis, rheumatoid arthritis, and more recently, acne, ischemic/reperfusion injury, inflammatory pain, and sickle cell anemia. Zileuton is currently approved for the prophylaxis and chronic treatment of asthma. We report the development and validation of a sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for the quantification of zileuton in human EDTA plasma. The range of reliable response was 3.05-20,000ng/mL in human plasma. The calibration curves had a correlation coefficient of r(2)>0.99. The intra-day precision was 3.4-5.3%. The inter-day precision ranged from 4.5% to 7.3% and inter-day accuracy from 100% to 107%. No matrix interferences, ion suppression/enhancement, or carry-over was observed. The assay met all predefined acceptance criteria and was subsequently employed to measure plasma zileuton concentrations in a clinical trial.
authors.affiliation: iC42 Clinical Research & Development, Department of Anesthesiology, University of Colorado Denver, Aurora, CO, USA. Electronic address: phillip.pian@ucdenver.edu.
authors.forename: Phillip
authors.initials: P
authors.lastname: Pian
authors.forename: Edward
authors.initials: E
authors.lastname: Labovitz
authors.forename: Keith
authors.initials: K
authors.lastname: Hoffman
authors.forename: Claudia F
authors.initials: CF
authors.lastname: Clavijo
authors.forename: Rachael
authors.initials: R
authors.lastname: Rzasa Lynn
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Galinkin
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Vinks
authors.forename: Punam
authors.initials: P
authors.lastname: Malik
authors.forename: Uwe
authors.initials: U
authors.lastname: Christians
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D006801:Humans; D006918:Hydroxyurea / Q000031:analogs & derivatives* / Q000097:blood / Q000737:chemistry; D016014:Linear Models; D016859:Lipoxygenase Inhibitors / Q000097:blood* / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D016859:Lipoxygenase Inhibitors; C063449:zileuton; D006918:Hydroxyurea
keywords: 5-Lipoxygenase inhibitor; Human plasma; LC–MS/MS; Zileuton