AN641 – Characterization of a polymorphous powder by DSC

INTRODUCTION

The characterization of crystal polymorphisms in drugs is an important point for the pharmaceutical industry. This importance is justified by the fact that the properties of a drug depends a lot on its polymorphic forms. One of the DSC important issue is the qualification of polymorphs and the determination of their stabilities.

AN-641

EXPERIMENTAL

Sample: pharmaceutical powder sample constituted by a mixture of polymorphs A and B.

DSC 131 Evo experimental conditions:

Sample mass: about 7 mg of powder

Experimental procedure:

Heating from room temperature to 250°C at 3°C/min.

Type of crucible : 100µl aluminum crucible closed with a perforated lid.

RESULTS

  • A sharp endothermic peak is observable above 200°C. It corresponds to the melting of the polymorph A.
  • Then the crystallization of the liquid phase into the form B produces an exothermic effect at higher temperature.
  • The melting peak of polymorph B is not detected in the studied range of temperature.
  • Polymorph B is more stable than the form A.