Abstract
The difference of stability and compatibility between the reference listed drug (RLD) and abbreviated new drug application (ANDA) formulations of enalapril maleate (EM) was evaluated using three thermoanalytical methods, including thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and thermomechanical analysis (TMA). TGA results showed high thermostability but no difference between formulations. DSC demonstrated an endothermic reaction between EM and NaHCO3 excipient, and indicating an incomplete reaction for the RLD formulation. TMA results showed differences between formulations. The most suitable pH or microenvironmental pH range that improved the stability of the EM formulation was also determined, finding that neutral pH promoted the highest stability, but that acidic conditions at pH 3 also stabilized the formulation. The mechanism for the stability of EM compounds based on their physical and chemical properties and the pKa of the compound itself was further proposed by us. These results can be used to improve the stability of other angiotensin-converting enzyme inhibitors with similar chemical structures.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.