LC-MS/MS assay for quantitation of enalapril and enalaprilat in plasma for bioequivalence study in Indian subjects.

Background: Enalapril (EPL) is an angiotensin-converting enzyme inhibitor for the treatment of hypertension and chronic heart failure. Enalaprilat (EPLT) is an active metabolite that contributes to the overall activity of EPL.

Aim: To quantitate EPL along with its metabolite EPLT using LC-MS/MS, a bioanalytical method was developed and validated with tolbutamide in human plasma using a protein precipitation technique.