title: Sensitive high-performance liquid chromatographic determination of cyclizine and its demethylated metabolite, norcyclizine, in biological fluids using coulometric detection.
abstract: An accurate, sensitive, selective and reproducible high-performance liquid chromatographic method with coulometric detection for the determination of cyclizine and its inactive demethylated metabolite, norcyclizine, in biological fluids has been developed. The drugs were separated using a custom packed reversed-phase C18 analytical column and phosphate buffer (0.05 M, pH 3)-acetonitrile (7:3) as mobile phase. The dual electrode coulometric detector was operated in the "oxidative-screen" mode with the upstream electrode (detector 1) set at 0.55 V and the downstream electrode (detector 2) set at 0.90 V. Serum and urine samples were prepared for analysis by solid-phase extraction, followed by a simple phase-separation step. The limit of quantitation was 1 ng/ml for both cyclizine and norcyclizine in serum and urine.
authors.affiliation: School of Pharmaceutical Sciences, Rhodes University, Grahamstown, South Africa.
authors.forename: R B
authors.initials: RB
authors.lastname: Walker
authors.forename: I
authors.initials: I
authors.lastname: Kanfer
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003501:Cyclizine / Q000031:analogs & derivatives* / Q000032:analysis* / Q000097:blood / Q000652:urine; D004563:Electrochemistry; D006801:Humans; D007202:Indicators and Reagents; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D007202:Indicators and Reagents; C029632:norcyclizine; D003501:Cyclizine