title: Enantioselective assay of beta-receptor antagonists present in microdialysis and plasma samples of rats.
abstract: The enantiomers of alprenolol, metoprolol, and propranolol have been separated on an enantioselective cellulase column and analysed using a fully automated HPLC system involving coupled column chromatography and fluorescence detection. The assays had sufficient selectivity and sensitivity to investigate the disposition of these beta 2-receptor antagonists in blood and brain extracellular fluid of rats. A cellulase column was used as the first column to separate the enantiomers giving separation factors between 2.9 and 4.3. After the separation, the enantiomers were trapped on two small precolumns by the use of a switching valve and were then introduced on an achiral C18 analytical column by eluting the small columns backward. The enantiomers in blood and brain tissue dialysates were analysed by direct injection of 8 microliters samples. The limit of quantitation was 0.025-0.4 micrograms/ml of the different enantiomers. Plasma samples were analysed after a simple extraction procedure. The intraassay precision of the lowest quality control plasma samples (0.2-0.8 micrograms rac-drug/ml) was 4-8% for the different enantiomers.
authors.affiliation: Medical Products Agency, Uppsala, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Johansson
authors.forename: P
authors.initials: P
authors.lastname: Sjöberg
authors.forename: A M
authors.initials: AM
authors.lastname: Hesselgren
authors.forename: T
authors.initials: T
authors.lastname: Salmonson
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000097:blood / Q000134:cerebrospinal fluid / Q000493:pharmacokinetics*; D000526:Alprenolol / Q000097:blood / Q000134:cerebrospinal fluid / Q000493:pharmacokinetics; D000818:Animals; D001921:Brain / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D008790:Metoprolol / Q000097:blood / Q000134:cerebrospinal fluid / Q000493:pharmacokinetics; D017551:Microdialysis; D011433:Propranolol / Q000097:blood / Q000134:cerebrospinal fluid / Q000493:pharmacokinetics; D051381:Rats; D013050:Spectrometry, Fluorescence; D013237:Stereoisomerism
chemical_list: D000319:Adrenergic beta-Antagonists; D000526:Alprenolol; D011433:Propranolol; D008790:Metoprolol