Pharmaceutical Antibiotics Enalapril Maleate Powder
Product Name: Enalapril maleate
Synonyms: 1-(n-(1-(ethoxycarbonyl)-3-phenylpropyl)-l-alanyl)-l-prolin(s)-l-prolin(z)-2-bu;1–l-alanyl]-l-prolin(s)-l-prolin(z)-2-but;mk421maleate;Enalapril Maleate USP24,25,EP2000;Enalapril maleate BP2000/USP25;ENALAPRIL MALEATE, IMP. I (EP): 1H-IMIDAZOLE MM(CRM STANDARD);ENALAPRIL MALEATE, IMP. D (EP): ETHYL(2S)-2-PYRAZIN-2-YL]-4-PHENYLBUTANOATE MM(CRM STANDARD);ENALAPRIL MALEATE, MM(CRM STANDARD)
Enalapril maleate Chemical Properties:
Melting point 143-144,5°C
Boiling point 0°C
alpha D25 -42.2° (c = 1 in methanol)
storage temp. -20°C Freezer
solubility methanol: ≥50 mg/mL, clear, colorless to yellow
pka pKa1 3.0; pKa2 (25°) 5.4
color white to off-white
Water Solubility Soluble in water, methanol, and ethanol.
Enalapril maleate Usage And Synthesis:
Chemical Properties White to Off-White Crystalline Powder
Uses An antihypertensive. An angiotensin-converting enzyme (ACE) inhibitor.
Similar With Enalaprilat:
Enalaprilat is the active metabolite of enalapril. It is the first dicarboxylate-containing ACE inhibitor and was developed partly to overcome these limitations of captopril. The sulfhydryl-moiety was replaced by a carboxylate-moiety, but additional modifications were required in its structure-based design to achieve a potency similar to captopril.
Enalaprilat, however, had a problem of its own. The consequence of the structural modifications was to give it ionisation characteristics that do not allow sufficient GI absorption for oral administration (in tablets). Thus, enalaprilat was only suitable for intravenous administration. This was overcome by the esterification of enalaprilat with ethanol to produce enalapril.
As a prodrug, enalapril is metabolized in vivo to the active form enalaprilat by various esterases. Peak plasma enalaprilat concentrations occur 2 to 4 hours after oral enalapril administration. Elimination thereafter is biphasic, with an initial phase which reflects renal filtration (elimination half-life 2 to 6 hours) and a subsequent prolonged phase (elimination half-life 36 hours), the latter representing equilibration of drug from tissue distribution sites.
The prolonged phase does not contribute to drug accumulation on repeated administration but is thought to be of pharmacological significance in mediating drug effects. Renal impairment results in significant accumulation of enalaprilat and necessitates dosage reduction. Accumulation is probably the cause of reduced elimination in healthy elderly individuals and in patients with concomitant diabetes, hypertension and heart failure.
Test ItemsQuality StandardResults
AppearanceA white or almost white crystalline powderAlmost white crystalline powder
SolubilityFreely soluble in methanol, sparingly soluble in water, practically insoluble in dichloromethaneConforms
IdentificationThe infrared absorption spectrum is concordant with Enalapril Maleate RS.Conforms
IdentificationThe retention time of the major peak in the chromatogram of Test solution corresponds to that in the chromatogram of the Standard solution, as obtained in the Assay.Conforms
Melting rangeAbout 144 ℃143~144 ℃
Specific rotation-41.0°~ -43.5°-41.7°
Loss on dryingNot more than 1.0%0.1%
Residue on ignitionNot more than 0.2%0.1%
Heavy metalsNot more than 0.001%＜0.001%
Residual solvents EthanolNot more than 0.5%＜LOD
Impurity(RRT=1.10)Not more than 1.0%N.D
Any other individual impurityNot more than 0.3%0.19%
Total impuritiesNot more than 1.0%0.33%
Assay98.0%~102.0%100.1%Antibiotics And Anticancer