Preparation and characterization of salt forms of enalapril.
Selection of an optimal salt form of a drug candidate is a vital component of preformulation stage of drug development. In this study, six salts of enalapril--citrate, mesylate, tartrate, malate, besylate and tosylate--were prepared and characterized by Mass Spectroscopy, Differential Scanning Calorimetry, Thermogravimetric Analysis, Microscopy, Powder X-ray Diffraction, Karl Fischer Titration, High Performance Liquid Chromatography, Fourier-Transform Infra-red Spectroscopy and Head Space Gas Chromatography. All the six salts were subjected to a tiered screening involving five stages in the following order: crystallinity, hygroscopicity, solubility, stability and flow/compactability. Enalapril malate showed encouraging profile because of its lower hygroscopicity, higher solubility, good solid state stability, and better flow and compactability, in comparison to the marketed maleate salt.
Kumar
Lokesh
L
Department of Pharmaceutical Technology (Formulations), National Institute of Pharmaceutical Education and Research (NIPER), S.A.S. Nagar, Punjab, India.
Amin
Aeshna
A
Bansal
Arvind K
AK
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical / Q000379:methods; D003460:Crystallization; D015195:Drug Design; D004355:Drug Stability; D004656:Enalapril / Q000737:chemistry*; D012492:Salts; D012995:Solubility
D000806:Angiotensin-Converting Enzyme Inhibitors; D012492:Salts; D004656:Enalapril