Almost all analytical laboratories supporting the pharmaceutical industry have both thermal analysis instruments and X-ray powder diffractometers. Combining DSC and XRD into one simultaneous measurement, thermal data and diffraction data on the same sample can obtain rich information.
The DSC and XRD data are collected on the same sample at the same time, so the thermal changes that occur can be directly correlated with the powder morphology and any structural changes can be assessed. In contrast, changes in powder morphology can be correlated with thermal changes to determine whether these changes are true structural changes or simply preferred orientation or maturation.
Various thermal changes, such as recrystallization, may involve multiple transformations through different metastable polycrystalline forms. Using thermal changes as an indication, the structure and powder fingerprint of metastable polycrystalline forms can be resolved by more detailed XRD scanning. This is a fast way to screen new solid forms.
