Differential scanning calorimetry preformulation studies

Thermal methods have found extensive use in the past as part of a program of preformulation studies, since carefully planned work can be used to indicate the existence of possible drug-excipient interactions in a prototype formulation [2], It should be noted, however, that the use of differential scanning calorimetry (DSC) for such work is less in vogue than it used to be. Nevertheless, in appropriately designed applications, thermal methods of analysis can be used to evaluate compound purity,... 

The measurement of IDR forms an important part of preformulation studies as they permit direct solubility and dissolution rate comparisons between different drug candidates, salts, polymorphic and pseudopolymorphic forms. The measurements are relatively straightforward to carry out but require a minimum of about 200mg of sample per determination. Production of the pellet can occasionally result in a pressure-induced polymorphism change the new polymorph may have different dissolution properties. Therefore, the presence or absence of a new polymorph should be verified by IR spectroscopy or by Differential Scanning Calorimetry (DSC). 

Rabel SR, Jona JA, Maurin MB. Applications of modulated differential scanning calorimetry in preformulation studies. J Pharm Biomed Anal 1999 21 339 -345. 

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