Simultaneous XRD-DSC identifies correct drug-polymer solubility and miscibility for enantiotropic solid forms.

Thermodynamic properties, including solubility and miscibility, which are highly correlated with amorphous solid dispersion physical stability were identified for the complex solid forms of bromopropamide using simultaneous X-ray diffraction (XRD)-differential scanning calorimetry (DSC). The most stable solid form of bromopropamide was crystallized and its crystal structure was solved. The crystallized material was characterized using simultaneous XRD-DSC measurements, which allowed dual analyses of a single sample.