Determining polymorphic purity by DSC

1 Confirming polymorphic purity using fast scan rates 

With the inhibition of the recrystallisation of form III to form I, it was shown that it is possible to measure the enthalpy of fusion directly from the calorimetric data 109.5 J/g, a value which can be estimated only from normal DSC experiments. It must be noted, however, that using fast scanning conditions in some cases cannot prevent this transition from occurring (due to the fast kinetics of the recrystallisation transition). 

Where polymorphic impurities exist as separate crystalline phases at trace levels in drug materials, accurate quantification is an important issue. Contamination of a drug material with 

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