title: Liquid-chromatographic determination of penbutolol and its principal metabolites in plasma and urine.
abstract: We describe a sensitive, specific liquid-chromatographic determination of penbutolol and its 4-hydroxy metabolite in plasma and urine. The method involves a simple organic extraction, evaporation of the solvent, reconstitution in methanol/water, and injection into the chromatograph. Penbutolol, its metabolites, and the internal standard, propranolol, are resolved on a CN reversed-phase column and detected fluorometrically. Conjugates of penbutolol and its 4-hydroxy metabolite may be determined after a 2-h enzymic hydrolysis. Detection limits are in the range of 3 to 12 micrograms/L of plasma. The assay is reproducible and nearly free of interferences. Representative concentrations in blood and urine of normal volunteers are reported.
mesh_terms: D000328:Adult; D002853:Chromatography, Liquid / Q000379:methods; D005453:Fluorescence; D006801:Humans; D006868:Hydrolysis; D008297:Male; D008875:Middle Aged; D010394:Penbutolol / Q000031:analogs & derivatives / Q000032:analysis*; D011412:Propanolamines / Q000032:analysis*; D012016:Reference Values; D013056:Spectrophotometry, Ultraviolet
chemical_list: D011412:Propanolamines; D010394:Penbutolol; C034270:4-hydroxypenbutolol