Crystallinity determination - Quantification of low amounts of amorphous material in a crystalline matrix and vice versa

This note compares the use of three different methods – X-ray diffraction, near infrared spectroscopy and differential scanning calorimetry – for quantifying small amounts of amorphous material in a crystalline matrix, and vice versa.

In this investigation we used alphalactose monohydrate as a model substance. In the pharmaceutical
industry this material is widely employed as a filler and diluent in tablets and capsules, as a carrier substance in dry powder inhalers and as a lyoprotectant during the freeze-drying of proteins.