title: Liquid chromatography-tandem mass spectrometry analysis of urinary fluticasone propionate-17beta-carboxylic acid for monitoring compliance with inhaled-fluticasone propionate therapy.
abstract: BACKGROUND
  Inhaled corticosteroids including fluticasone propionate (FP) are the most effective treatment for persistent-asthma. Noncompliance ranging from 20% to 80% of treated patients is associated with substantial health care costs, morbidity and fatalities. A noninvasive test to assess FP treatment compliance is needed. The major metabolite of FP is FP-17beta-carboxylic acid (FP17betaCA) and is excreted in urine. This study demonstrates the development of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay to measure FP17betaCA in urine and evaluation of FP17betaCA urinary elimination.
  
  
  METHODS
  Fluorometholone was used as the internal standard. After acetonitrile precipitation, samples were extracted with dichloromethane, washed and dried. Reconstituted extract (60 microL) was subjected to reversed-phase chromatography and positive-ion mode LC-MS/MS analysis. Assay precision, linearity, recovery and sample stability were determined. Elimination evaluation included measurement of FP17betaCA in urine collected daily from human subjects before (day 1), during treatment (days 2-5; dose FP-110 microg 2 puffs/day), and following cessation of FP therapy (days 6-14; n=4).
  
  
  RESULTS
  Linear range of the FP17betaCA assay was 10.3-9510pg/mL. Limit of quantitation (LOQ) was 10.3 pg/mL and recovery ranged from 85.8% to 111.9%. Inter-assay CVs were 7.4-12.0% for FP17betaCA concentrations of 11.1-5117 pg/mL. Urine FP17betaCA was absent in subjects prior to FP therapy, detectable (180-1991 ng FP17betaCA/g creatinine) throughout the dosing period and reached below the LOQ at 6 days after therapy cessation.
  
  
  CONCLUSIONS
  Measurement of FP17betaCA by LC-MS/MS has acceptable analytical performance for clinical use. These data support the clinical utility of measuring FP17betaCA in urine to monitor patient compliance with FP therapy.
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, 200 1st Street S.W., Rochester, MN 55905, USA.
authors.forename: Nichole L
authors.initials: NL
authors.lastname: Korpi-Steiner
authors.forename: Brian C
authors.initials: BC
authors.lastname: Netzel
authors.forename: Jesse C
authors.initials: JC
authors.lastname: Seegmiller
authors.forename: John B
authors.initials: JB
authors.lastname: Hagan
authors.forename: Ravinder J
authors.initials: RJ
authors.lastname: Singh
mesh_terms: D000328:Adult; D000730:Androstadienes / Q000737:chemistry / Q000378:metabolism / Q000493:pharmacokinetics / Q000652:urine*; D018926:Anti-Allergic Agents / Q000008:administration & dosage / Q000737:chemistry / Q000652:urine; D001249:Asthma / Q000188:drug therapy*; D002853:Chromatography, Liquid / Q000379:methods*; D016903:Drug Monitoring; D005260:Female; D000068298:Fluticasone; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D015394:Molecular Structure; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000730:Androstadienes; D018926:Anti-Allergic Agents; C549234:fluticasone propionate-17-carboxylic acid; D000068298:Fluticasone