Characterisation of polymorphs by DSC

There are a number of methods that can be used to characterise polymorphs of a drug substance. Demonstration of a non-equivalent structure by single-crystal X-ray diffraction [ 11 ] is currently regarded as the definitive evidence of polymorphism. X-ray powder diffraction (XRPD) can also be used to support the existence of polymorphs. However supporting 

Many examples exist in the literature of studies using DSC as a method for predicting the presence of polymorphs of a compound [ 14]. A recent example is that of carbamazepine, a drug used in the treatment of epilepsy. It has been shown successfully using DSC that three distinct polymorphs of carbamazepine exist. These findings were backed up by results obtained from Fourier transform infrared (FTIR) and XRPD experiments [15]. However, 

II stable transition Transition reversible Transition irreversible 

Solubility 1 higher transition Solubility 1 always lower than II 

Solubility 1 lower transition Transition II 1 endothermic Transition II 1 endothermic 

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