Determination of dextromethorphan and its O-demethylated metabolite from urine.
A high-performance liquid chromatography (HPLC) assay for the simultaneous quantitation of dextromethorphan and its O-demethylated metabolite dextrorphan from urine is described. A cyano analytical column was used with a mobile phase consisting of MeOH 16%, acetonitrile 3%, and triethylamine 0.06% at pH 2.8 and a flow rate of 1.0 ml/min. Betaxolol was used as the internal standard. Standard curves from 50 ng/ml to 10,000 ng/ml (dextrorphan), and from 50 ng/ml to 8,000 ng/ml (dextromethorphan) were developed. The peaks eluted at 7.8 min (dextrorphan), 12.2 min (betaxolol), and 17.8 min (dextromethorphan). The coefficients of variance ranged from 1.3 to 4.5% at 250 ng/ml and 0.9 to 2.5% at 5,000 ng/ml. This assay was used to determine dextromethorphan/dextrorphan molar ratios in healthy male volunteers for the purpose of determining phenotype status for the P450IID6 isozyme.
Marshall
P S
PS
Department of Pharmacy Practice, College of Pharmacy, University of Minnesota, St. Paul.
Straka
R J
RJ
Johnson
K
K
D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003915:Dextromethorphan / Q000652:urine*; D003917:Dextrorphan / Q000652:urine*; D005069:Evaluation Studies as Topic; D006801:Humans; D008297:Male; D010641:Phenotype
D003917:Dextrorphan; D003915:Dextromethorphan