Determination of the angiotensin converting enzyme inhibitor benazeprilat in plasma and urine by an enzymic method.
An enzyme inhibition assay for the angiotensin-converting enzyme (ACE) inhibitor benazeprilat is described. Plasma and urine samples were diluted and endogenous ACE was inactivated by heating. After incubation of the plasma samples with hippuryl-histidyl-leucine as substrate and blank plasma as the source of ACE, released hippuric acid was measured by high-performance liquid chromatography. Urine samples were incubated with [3H] hippuryl-glycyl-glycine and with rabbit lung extract as the source of ACE. Released [3H] hippuric acid was quantified by liquid scintillation counting. Drug standards for the standard curve were prepared in the biological matrix. A cross-check with a gas chromatographic-mass spectrometric method showed good agreement, demonstrating that this enzymic method is suitable for assessing drug bioavailability and pharmacokinetics.
Graf
P
P
Research and Development Department, CIBA-GEIGY Limited, Basle, Switzerland.
Frueh
F
F
Schmid
K
K
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000032:analysis* / Q000097:blood / Q000652:urine; D001552:Benzazepines / Q000032:analysis* / Q000097:blood / Q000652:urine; D002851:Chromatography, High Pressure Liquid; D008401:Gas Chromatography-Mass Spectrometry; D006626:Hippurates / Q000032:analysis; D006801:Humans; D007202:Indicators and Reagents; D008297:Male; D007703:Peptidyl-Dipeptidase A
D000806:Angiotensin-Converting Enzyme Inhibitors; D001552:Benzazepines; D006626:Hippurates; D007202:Indicators and Reagents; D007703:Peptidyl-Dipeptidase A; C052133:benazeprilat