Paracetamol (Paracetaminophen) ist sowohl in den Vereinigten Staaten als auch in Europa das am häufigsten verwendete Medikament gegen Schmerzen und Fieber. Es lohnt sich jedoch nicht, Kopfschmerzen zu bekommen, wenn man über seine physikalisch-chemischen Eigenschaften nachdenkt. Die thermische Analyse, insbesondere die Dynamische Differenzkalorimetrie (DSC), ist von großer Hilfe.
Paracetamol (acetaminophen) is the most commonly used medication for pain and fever in both the United States and Europe. However, it is not worth getting a headache when you think about its physicochemical properties. Thermal analysis, and especially differential scanning calorimetry (DSC), is of great help.
From the chemical point of view, diamonds are just made of carbon. The phenomenon that chemical elements can occur in different forms within the same phase, i.e., in different structural modifications, is called allotropy. Due to the relationship between crystal modification and melting point, Differential Scanning Calorimetry (DSC) is ideally suited to discriminate between different polymorphic forms. A more general term for chemical compounds is polymorphism.
When making sure pharmaceuticals comply to quality standards, there are four areas where Thermal Analysis can help to determine potential problems. This article will explain those Terms.
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.