enalapril and hippuric-acid

A high-performance liquid chromatographic method for indirect determination of enalapril in human plasma, was developed and validated. An exogenous angiotensin converting enzyme after drug inhibition was determined by reacting with hippuryl-histidyl-leucine to produce hippuric acid (HA) which was inversely proportional to the amount of enalaprilat in plasma. The HPLC was carried out on a Lichrosphere 60RP-select B, C18, 5 microm (125 mm x 4.0 mm i.d.) column at flow rate of 1.0 ml/min. The analysis time per injection was within 6.5 min. The lowest concentration of enalaprilat to be quantitated was 3.0 ng/ml with the acceptable accuracy and precision. This successfully developed method was practically and accurately used for pharmacokinetics and bioequivalent study of enalapril.

Topics: Adult; Angiotensin-Converting Enzyme Inhibitors; Calibration; Chromatography, High Pressure Liquid; Enalapril; Enalaprilat; Hippurates; Humans; Kinetics; Male; Peptidyl-Dipeptidase A; Reference Standards; Reproducibility of Results; Solutions; Spectrophotometry, Ultraviolet; Temperature