Analysis of Polymorphism | Investigating Polymorphism (Thermal Analysis)

Different crystalline forms of a substance are generally said to have different solubilities. Polymorphism in foods results in different meltability in the mouth; and in pharmaceuticals, it results in different drug efficacy due to changes in solubility in the body.
Polymorphism can be easily measured by DSC.

A sulfathiazole sample was measured using a Thermal Analyzer.
Fig. 1 exhibits endothermic peaks at 168.3°C and 202.2°C. However, in Fig. 2, the peak at 168.3°C is missing for the sulfathiazole sample that was heated to 185°C.
The 168.3°C peak suggests the existence of an unstable crystalline form.

Fig. 1 DSC Curve of Sulfathiazole (Original)

Fig. 2 DSC Curve of Sulfathiazole (Heated to 185 ºC)

Simultaneous Thermogravimetric/Differential Thermal Analyzer

A newly developed high-sensitivity detector doubles the previous peak heights. The 1 µW (RMS) max. noise level permits cooling measurements without the need for options. The Automatic detector can also be cleaningcleaned automatically.