title: Validation of a high-pressure liquid chromatography and fluorescence polarization immunoassay for the determination of methadone in canine plasma.
abstract: Methadone is a synthetic opiate derivative that possesses analgesic activity. A modified fluorescence polarization immunoassay (FPIA) method and a high-pressure liquid chromatography (HPLC) method with UV detection were compared for measurement of concentrations of methadone in canine plasma following intravenous and oral methadone administration. The mean+/-SD for accuracy (deviation from actual concentration) and precision (coefficient of variation) when methadone-fortified canine plasma was evaluated with the FPIA method were 3.9+/-3.2% and 4.4+/-2.9%, respectively. The accuracy and precision of the HPLC method were 6.2+/-5.2% and 7.7+/-3.9%, respectively. The limit of quantification for the FPIA and HPLC methods were 25 and 20 ng/mL, respectively. The coefficient of determination (r) between FPIA and HPLC analysis was 0.94 when plasma from dogs dosed with methadone was evaluated. FPIA provides a rapid, sensitive, and specific measurement of methadone in canine plasma following oral and intravenous administration.
authors.affiliation: Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina 27606, USA. butch_kukanich@ncsu.edu
authors.forename: Butch
authors.initials: B
authors.lastname: KuKanich
authors.forename: B Duncan
authors.initials: BD
authors.lastname: X Lascelles
authors.forename: Mark G
authors.initials: MG
authors.lastname: Papich
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004285:Dogs; D005260:Female; D016231:Fluorescence Polarization Immunoassay / Q000379:methods*; D008297:Male; D008691:Methadone / Q000097:blood*
chemical_list: D008691:Methadone