Low-Frequency Raman Spectroscopic Study on Compression-Induced Destabilization in Melt-Quenched Amorphous Celecoxib.

A series of melt-quenched disks of amorphous celecoxib were obtained using two different cooling rates (>100 °C/min and ∼25-30 °C/min) and subjected to different compression pressures (125, 250, and 500 MPa) and dwell times (0, 30, and 60 s). The kinetics of crystallization for these differently prepared melt-quenched disks were probed using a number of methods. Low-frequency Raman spectroscopy was used to monitor isothermal crystallization kinetics, whereas dynamic differential scanning calorimetry served as a complimentary technique to identify changes in form. Although both compression parameters destabilized the amorphous celecoxib, the dwell time was found to have a more critical overall effect. Additionally, the sample history was affirmed to be a factor for limiting the magnitude of compression-induced destabilization.