title: Multidimensional narrow bore liquid chromatography analysis of Ro 24-0238 in human plasma.
abstract: A highly sensitive LC method has been developed and validated for quantitation of Ro 24-0238 in human plasma using Ro 24-2446 as an internal standard. With 1 ml of plasma, the limit of quantitation of the method was 50 pg ml-1 of Ro 24-0238. After solid-phase extraction with C18 reversed-phase cartridges, the samples were reconstituted in an acidic buffer solution; under these conditions, Ro 24-0238 and Ro 24-2446 (IS) were converted to their cationic forms. The LC system employed a strong cation exchange column and a narrow bore reversed-phase column, connected via a column switching valve. The cationic analyte and internal standard were separated from most of the endogenous components of plasma on the cation exchange column. A small fraction containing the analyte and the internal standard was transferred by automated valve switching to the narrow bore reversed-phase column, which further resolved the individual components. The chromatography was monitored by UV absorption at 322 nm. The overall intra-assay precision was 3.6% (RSD) and the per cent error was less than +/- 11%. The overall inter-assay precision was 3.9% (RSD). Linearity was demonstrated in a concentration range of 50-5000 pg ml-1. This method has been applied to pharmacokinetic studies of Ro 24-0238 in man.
authors.affiliation: Department of Drug Metabolism and Pharmacokinetics, Hoffmann-La Roche Inc., Nutley, NJ 07110.
authors.forename: K A
authors.initials: KA
authors.lastname: Wang
authors.forename: R W
authors.initials: RW
authors.lastname: Blain
authors.forename: A J
authors.initials: AJ
authors.lastname: Szuna
mesh_terms: D001774:Blood Chemical Analysis / Q000379:methods*; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D005231:Fatty Acids, Unsaturated / Q000032:analysis; D006801:Humans; D010972:Platelet Activating Factor / Q000032:analysis / Q000037:antagonists & inhibitors*; D053284:Polyunsaturated Alkamides; D011725:Pyridines / Q000032:analysis; D012015:Reference Standards; D015203:Reproducibility of Results
chemical_list: D005231:Fatty Acids, Unsaturated; D010972:Platelet Activating Factor; D053284:Polyunsaturated Alkamides; D011725:Pyridines; C086948:Ro 24-2446; C073133:Ro 24-0238