– Cilazapril, also known as Ro 31 2848, is a potent ACE inhibitor used for hypertension. Cilazapril is a prodrug that is hydrolyzed after absorption to its main metabolite cilazaprilat. Cilazapril is a monoethyl ester, which acts as an angiotensin-converting enzyme (ACE) inhibitor. The inhibitor functions by inhibiting the ability of ACE to cleave bonds of angiotensin I and Hip-His-Leu. It is known that the diacid form of Cilazapril is more potent that enalapril at inhibiting ACE.