title: High-performance liquid chromatographic determination of diltiazem and two of its metabolites in plasma using a short alkyl chain silanol deactivated column.
abstract: A simple and reproducible method for the determination of diltiazem and its two major metabolites, demethyl- and deacetyldiltiazem, is presented using a new column containing a short alkyl chain silanol deactivated support. This method involves the extraction of alkalinized plasma with a hexane-isopropanol mixture (95:5, v/v) followed by back-extraction into 5 mM sulfuric acid. Reversed-phase liquid chromatography is used with ultraviolet detection at 237 nm over a concentration range of 20-400 ng/ml for the compounds. Imipramine is used as the internal standard. Within-day and between-day coefficients of variation are less than 10%. The lower limits of detection are 4, 2 and 4 ng/ml for diltiazem, deacetyl- and demethyldiltiazem, respectively. Samples can be stored for up to thirty days with no significant degradation. The assay has clinical applicability.
authors.affiliation: College of Pharmacy, University of Florida, Gainesville 32610.
authors.forename: D R
authors.initials: DR
authors.lastname: Rutledge
authors.forename: A H
authors.initials: AH
authors.lastname: Abadi
authors.forename: L M
authors.initials: LM
authors.lastname: Lopez
authors.forename: C A
authors.initials: CA
authors.lastname: Beaudreau
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004110:Diltiazem / Q000031:analogs & derivatives / Q000097:blood* / Q000493:pharmacokinetics; D006801:Humans; D006973:Hypertension / Q000097:blood; D007202:Indicators and Reagents; D008297:Male; D012821:Silanes / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet
chemical_list: D007202:Indicators and Reagents; D012821:Silanes; C082343:silanol; C037769:deacetyldiltiazem; D004110:Diltiazem; C052825:N-monodemethyldiltiazem