Enalaprilat API is the active dicarboxylic-acid metabolite of enalapril and belongs to the angiotensin-converting enzyme (ACE) inhibitor class. Enalaprilat directly inhibits ACE, an enzyme responsible for the conversion of angiotensin I to angiotensin II. By reducing angiotensin II formation, Enalaprilat contributes to vasodilation and reduction of blood pressure.
Enalaprilat is commonly handled as Enalaprilat Dihydrate, a crystalline pharmaceutical substance with the molecular formula C₁₈H₂₄N₂O₅·2H₂O and molecular weight 384.42 g/mol. The USP monograph identifies Enalaprilat Dihydrate as the dihydrate form and specifies its content on an anhydrous basis.
Enalaprilat is the pharmacologically active metabolite formed when the ethyl ester group of enalapril is hydrolyzed to the corresponding carboxylic acid. Unlike enalapril, Enalaprilat has poor oral absorption and is used in pharmaceutical products administered by intravenous injection.
Enalaprilat Dihydrate is described as a white or almost white, hygroscopic, crystalline powder. It is very slightly to slightly soluble in water, sparingly soluble in methanol and practically insoluble in acetonitrile. The substance exhibits pseudopolymorphism.
Enalaprilat acts as a competitive ACE inhibitor. It inhibits the conversion of angiotensin I to angiotensin II, reducing the vasoconstrictor and aldosterone-promoting effects of angiotensin II. This results in decreased vascular resistance and contributes to blood-pressure reduction.
Enalaprilat is associated with pharmaceutical applications involving:
Swapnroop Drugs and Pharmaceuticals provides Enalaprilat API / Enalaprilat Dihydrate for qualified pharmaceutical manufacturing, formulation development and pharmaceutical research requirements.
Enalaprilat is a specialized cardiovascular API requiring controlled analytical testing for assay, related substances, water content, optical rotation, sulfated ash and bacterial endotoxins, as applicable to the pharmacopoeial specification.
Enalaprilat Dihydrate quality is evaluated using appropriate pharmacopoeial analytical procedures. The BP/Ph. Eur. monograph specifies identity by specific optical rotation and infrared absorption spectrophotometry, related substances by liquid chromatography, water content, sulfated ash, bacterial endotoxins and assay.
The BP/Ph. Eur. monograph specifies storage of Enalaprilat Dihydrate in an airtight container.
For pharmaceutical manufacturing, storage and handling should follow the applicable approved specification, manufacturer documentation and regulatory requirements.
| Parameter | Specification |
|---|---|
| Assay (HPLC) | 98.5% – 101.5% |
| Loss on Drying | NMT 1.0% |
| Residue on Ignition | NMT 0.1% |
| Heavy Metals | NMT 20 ppm |
| Individual Impurity | NMT 0.5% |
| Total Impurities | NMT 1.0% |
| Water Content | 7.0% – 11.0% |
| Melting Point | −53.0° to −56.0° |
| Solubility | Very slightly/slightly soluble in water; sparingly soluble in methanol; practically insoluble in acetonitrile |