title: Simultaneous determination of nefiracetam and its metabolites by high-performance liquid chromatography.
abstract: A reversed-phase high-performance liquid chromatographic assay was developed to simultaneously quantitate nefiracetam (NEF), a novel nootropic agent, and its three known oxidized metabolites (N-[(2,6-dimethylphenylcarbamoyl)methyl]succinamic acid (5-COOH-NEF), 4-hydroxy-NEF and 5-hydroxy-NEF) in human serum and urine. The quantitative procedure was based on solid-phase extraction with Sep-Pak C18 and ultraviolet detection at 210 nm. The calibration curves of NEF and the metabolites were linear over a wide range of concentrations (0.5-21.5 nmol/ml for NEF and 0.4-9.5 nmol/ml for metabolites in serum and 4-86 nmol/ml for NEF and 8-190 nmol/ml for metabolites in urine). Intra- and inter-day assay coefficients of variation for the compounds were less than 10%. The limit of detection was 0.1 nmol/ml for NEF, 5-COOH-NEF and 4-hydroxy-NEF, and 0.2 nmol/ml for 5-hydroxy-NEF in both serum and urine. This method is applicable for the determination of NEF and its metabolites in human serum and urine with satisfactory accuracy and precision.
authors.affiliation: Drug Metabolism and Analytical Chemistry Research Center, Daiichi Pharmaceutical Co. Ltd., Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Fujimaki
authors.forename: K
authors.initials: K
authors.lastname: Sudo
authors.forename: H
authors.initials: H
authors.lastname: Hakusui
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D011619:Psychotropic Drugs / Q000097:blood* / Q000652:urine*; D011760:Pyrrolidinones / Q000097:blood* / Q000652:urine*
chemical_list: D011619:Psychotropic Drugs; D011760:Pyrrolidinones; C058876:nefiracetam