Apparent Melting: A New Approach To Characterizing Crystalline Structure In Pharmaceutical Materials

Differential Scanning Calorimetry (DSC) is an analytical technique frequently used to detect and quantify crystalline content of pharmaceuticals, foods, polymers, and numerous other materials. During heating in a DSC experiment, the presence of crystalline structure is seen as an endothermic peak. The temperature and area of the peak can be utilized to help identify, qualify, and quantify crystalline structure. Most DSC users and materials researchers will typically know or suspect if their material contains crystalline content.

A DSC thermogram containing an endothermic peak is often interpreted as “thermodynamic melting” of crystalline structure, but this interpretation of the data may not always be correct.

Since crystalline structure is lost by both True and Apparent melting, some may think it makes no difference in the usefulness and application of the DSC data. Learn why this assumption is false in addition to how the accuracy (melting temperature and heat of fusion) and utility of the data are greatly diminished for materials that undergo Apparent Melting.