title: GLC assay of verapamil in plasma: identification of fluorescent metabolites after oral drug administration.
abstract: The fluorometric assay for verapamil in plasma is not useful after oral drug administration because of interference by inactive, but fluorescent, metabolites extracted along with the parent drug. A GLC method using a flame-ionization detector after silylation allows the separation of unchanged active verapamil from the metabolites and quantitation to a sensitivity of 0.025 microgram/ml. After a single oral dose of drug in dogs, up to 80% of "fluorescent verapamil" represented inactive metabolites.
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001711:Biotransformation; D002849:Chromatography, Gas; D004285:Dogs; D007700:Kinetics; D008722:Methods; D013050:Spectrometry, Fluorescence; D014700:Verapamil / Q000008:administration & dosage / Q000097:blood*
chemical_list: D014700:Verapamil