title: A time-resolved fluorescence immunoassay for the determination of a novel respiratory therapeutic agent, AR-C68397XX (Viozan) in human plasma.
abstract: A dissociation-enhanced lathanide fluorescence immunoassay (DELFIA) method has been developed for the determination of AR-C68397XX, a novel respiratory therapeutic agent, in human plasma. The method is a 'direct' immunoassay and provides an alternative to the solid phase extraction RIA described in a previous publication, which employs the same specific antiserum. The DELFIA method is suitable for the determination of the analyte at pg ml(-1) concentrations. The non-isotopic label was prepared by complexation of a DTPA derivative of AR-C68397XX with free europium cation (Eu3+). Plasma samples were diluted at least 5-fold prior to analysis to eliminate matrix interference. The calibration range is 10-2000 pg ml(-1), and the LOQ of the method is 50 pg ml(-1) using 50 microl of diluted human plasma sample.
authors.affiliation: Department of Drug Development Metabolism and Bioanalysis, AstraZeneca R&D Charnwood, Loughborough, Leics., UK. viv.willson@astrazeneca.com
authors.forename: V J
authors.initials: VJ
authors.lastname: Willson
authors.forename: W J
authors.initials: WJ
authors.lastname: Lockley
authors.forename: A
authors.initials: A
authors.lastname: Mather
authors.forename: J
authors.initials: J
authors.lastname: Singh
authors.forename: C M
authors.initials: CM
authors.lastname: Gilbert
authors.forename: M A
authors.initials: MA
authors.lastname: Bayliss
authors.forename: D
authors.initials: D
authors.lastname: Wilkinson
mesh_terms: D000318:Adrenergic beta-Agonists / Q000097:blood* / Q000627:therapeutic use; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008173:Lung Diseases, Obstructive / Q000188:drug therapy; D015203:Reproducibility of Results; D013844:Thiazoles / Q000097:blood* / Q000627:therapeutic use
chemical_list: D000318:Adrenergic beta-Agonists; D013844:Thiazoles; C116267:sibenadet