title: [Column switching HPLC method for determination of dextrorphan, an active metabolite of dextromethorphan, in plasma].
abstract: An HPLC method for the determination of dextrorphan, an active metabolite of dextromethorphan, in plasma was established using column switching technique. The column switching system was equipped with a per-column of 30 mm x 5 mm ID, packed with mu Bondapak C18, 37-50 microns, and an analytical column of 150 mm x 5 mm ID, packed with YWG-C18, 5 microns. A 0.2% acetic acid solution was used as the pretreating mobile phase to wash out impurities from the per-column. The analytical mobile phase consisted of acetonitrile-water-acetic acid-triethylamine-dichloromethane (17:82:1:0.05:0.025). The plasma samples were directly injected into the HPLC system after enzymatic hydrolysis of dextrorphan glucuronide ester conjugate to free form with beta-glucuronidase. The dextrorphan was monitored with a fluorescence detector at 290 nm (excitation) and 315 nm (emission). The method was linear within the plasma concentration range of 20-640 ng/ml (r = 0.9987), and the detection limit was 4 ng/ml. The mean recoveries of the method averaged 103.8%. The relative standard deviations of the assay were less than 10% for both within-day and between-days.
authors.affiliation: College of Pharmacy, Second Military Medical University, Shanghai.
authors.forename: L L
authors.initials: LL
authors.lastname: Liu
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: X T
authors.initials: XT
authors.lastname: Feng
authors.forename: S
authors.initials: S
authors.lastname: Gao
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003915:Dextromethorphan / Q000493:pharmacokinetics*; D003917:Dextrorphan / Q000097:blood*; D006801:Humans
chemical_list: D003917:Dextrorphan; D003915:Dextromethorphan