title: Application of solid-phase extraction in the determination of U-82217 in rat serum, urine and brain.
abstract: The techniques of solid-phase extraction (SPE) were applied in the analytical method development for the determination of U-82217, 3-(5-cyclopropyl-1,2,4-oxadiazol-3-yl)-5-[(4-methoxyphenyl)methyl] -imidazo[1,5-a]quinoxalin-4(5H)-one, in rat serum, urine and brain. Samples of serum, urine or brain homogenate containing U-82217 were loaded on C18 SPE columns and eluted with acetonitrile (300 microliters). The prepared samples were analyzed by reversed-phase HPLC using an ODS column with a mobile phase of acetonitrile-water (45:55, v/v) containing 0.12% of acetic acid (pH 6.0 +/- 0.1). The UV absorbance of the column effluent was monitored at a wavelength of 318 nm. The absolute extraction recovery from serum, urine and brain samples was ca. 90%. Linear calibration graphs were obtained over the ranges 5 ng/ml-20 micrograms/ml (serum), 20 ng/ml-20 micrograms/ml (urine) and 50 ng/g-200 micrograms/g (brain). The intra- and inter-assay precision and accuracy were all found to be < 13% at the concentrations evaluated. The strategy in SPE development and the application of this method to the determination of U-82217 in rat serum and brain for a pharmacokinetic study are also discussed.
authors.affiliation: Drug Metabolism Research, Upjohn Laboratories, Kalamazoo, MI 49001.
authors.forename: W Z
authors.initials: WZ
authors.lastname: Zhong
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D002851:Chromatography, High Pressure Liquid; D002853:Chromatography, Liquid / Q000379:methods*; D006993:Hypnotics and Sedatives / Q000032:analysis* / Q000097:blood / Q000652:urine; D010069:Oxadiazoles / Q000032:analysis*; D011810:Quinoxalines / Q000032:analysis*; D051381:Rats; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet
chemical_list: D006993:Hypnotics and Sedatives; D010069:Oxadiazoles; D011810:Quinoxalines; C079539:U 82217