Many pharmaceutical solids exhibit polymorphism, i.e., the ability of a substance to exist in different crystalline forms. The polymorphic form can have significant influence on pharmaceutical processing and can, for example, affect grinding, granulation and tabletability. A DSC measurement allows for the characterization of the present modification. Here, different modifications of paracetamol are distinguished by means of DSC.
Caffeine exists under 2 polymorphic forms (I and II). Compression of form I induces its transformation into form II, leading to changes in its properties. Heating with DSC ensures that caffeine is in the correct form.
How to determine the shelf life of drugs without long time testing? First predictions about the shelf-life concerning thermal stability are achieved using thermogravimetric measurements with a kinetics Evaluation. This occurs within some hours or days.