Determination of enalapril and enalaprilat in small human serum quantities for pediatric trials by HPLC-tandem mass spectrometry.

The angiotensin converting enzyme-inhibitor enalapril is the prodrug of enalaprilat and used in the treatment pediatric hypertension and chronic heart failure. Pharmacokinetic data are lacking to provide adequate dosing and for pediatric pharmacotherapeutical trials it is imperative to minimize sample volume. Therefore an HPLC-tandem mass spectrometry (MS) method for the determination of enalapril and enalaprilat in 100 μL of human serum was developed and validated with benazepril as internal standard (IS).