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How to Evaluate Solid Pharmaceutical Drugs (1): Confirming the Crystal Form of an API

AppNote XRD1001: How to Evaluate Solid Pharmaceutical Drugs (1): Confirming the Crystal Form of an API


Active pharmaceutical ingredients (APIs) may undergo phase transitions to crystal polymorphs or pseudo-crystal polymorphs due to temperature, humidity, etc. Distinguishing each crystal polymorph and performing quantification are necessary in the development and production of pharmaceuticals when multiple crystal or pseudo-crystal polymorphs are present, since each crystalline polymorph has a different solubility and rate of absorption into the body.

Because they have different crystal structures, crystalline polymorphs and pseudo-polymorphs of a given compound show different profiles in powder X-ray diffraction measurements (XRD) and differential scanning calorimetry measurements (DSC).

We would like to introduce how to determine the crystal structure of a sample containing crystal polymorphs.

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