Monitoring of Isothermal Crystallization and Time-Temperature Transformation of Amorphous Felodipine: The Time-Domain Nuclear Magnetic Resonance Method.

The isothermal crystallization process of felodipine has been investigated using the time-domain Nuclear Magnetic Resonance (NMR) method for amorphous bulk and ground samples. The obtained induction and crystallization times were then used to construct the time-temperature-transformation (TTT) diagram, both above and below the glass transition temperature (T). The Nose temperature was found equal to 363 K. Furthermore, the dynamics of crystalline and amorphous felodipine were compared across varying temperatures. Molecular dynamics simulations were also employed to explore the hydrogen-bond interactions and dynamic properties of both systems.