Blog Date 29 March, 2023


Cat. No. Q020000A

CAS. No. 85441-61-8

Quinapril is a member of the class of isoquinolines .It is chemically described as (S)-2-((S)-2-(((S)-1-ethoxy-1-oxo-4-phenylbutan-2-yl) amino) propanoyl)-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid in which the alpha-amino group of the alanyl residue has been substituted by a 1-ethoxycarbonyl-4-phenylbutan-2-yl group (the all-S isomer). Its molecular formula is C25H30N2Oand its molecular weight is 438.52 g/mol.

Quinapril is used for treatment of hypertension and patented in 1980 and came into medical use in 1989. It is available as a generic medication. In 2020.

A prodrug for quinaprilat (by hydrolysis of the ethyl ester to the corresponding carboxylic acid), it is used as an angiotensin-converting enzyme inhibitor (ACE inhibitor) used (generally as the hydrochloride salt) for the treatment of hypertension and congestive heart failure.

 Quinapril is used to treat high blood pressureheart failure and diabetic kidney disease. It may be used for the treatment of hypertension by itself or in combination with thiazide diuretics, and with diuretics and digoxin for heart failure.

 Quinaprill is a white to off-white amorphous powder that is freely soluble in aqueous solvents. Quinapril tablets contain 5 mg, 10 mg, 20 mg, or 40 mg of quinapril for oral administration. Each tablet also contains candelilla wax, crospovidone, gelatin, lactose, magnesium carbonate, magnesium stearate, synthetic red iron oxide, and titanium dioxide. Quinapril is in a class of medications called angiotensin-converting enzyme (ACE) inhibitors. It works by decreasing certain chemicals that tighten the blood vessels, so blood flows more smoothly and the heart can pump blood more efficiently


Quinapril is a non-sulphylhydryl ACE inhibitor that acts by blocking the action of Angiotensin Converting Enzyme (ACE), which plays a vital role in the renin-angiotensin-aldosterone system (RAAS). Quinapril is metabolized into quinaprilat in the liver, where the drug enters circulation. After conversion, the liver releases quinaprilat into the peripheral circulation, inhibiting ACE; the enzyme is responsible for converting angiotensin I to angiotensin II.

Angiotensin II is the hormone that promotes the stimulation of the hormone aldosterone, which is responsible for salt and water retention. A combination of salt and water retention, coupled with peripheral vasculature constriction, leads to the development of systemic hypertension.

Quinapril (and its metabolite quinaprilat) decreases systemic (peripheral and renal) vascular resistance, thereby decreasing blood pressure.

Distribution is widespread, except for brain tissue. The renal system clears the majority of quinapril, and the maximum observable effect of ACE inhibitors takes place at 5 hours.

Some of the impurities of quinapril are as follows:

Catalogue No


Product Name


Cas No



Quinapril Hydrochloride






Quinapril USP Related Compound A






Quinapril for system suitability






Quinapril ethyl ester






Quinapril ethyl ester maleic acid salt






Quinapril EP Impurity I Hydrochloride




 To enquire for many more impurities ofQuinapril follow the link given below:

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