Use of the Pair Distribution Function Analysis in the Context of Pharmaceutical Materials
Résumé
The processing of pharmaceutic materials increasingly involves physical treatments aiming at improving their bio-availability through reduction of the powder grain size. This goes along with a strong degradation of their crystallinity and new methods must be applied to investigate their structural arrangement. One on the most powerfull emerging methods in this respect is the analysis of the Pair Distribution Function. Obtained from the Fourier transform of the structure function, it represents in direct space the probability of finding atoms at a given distance in a sample and therefore yields a multi-scale description of its atomic arrangement disregarding the sample crystalline state. We describe here the definition, measurement and use of the Pair Distribution Function in the context of disordered pharmaceutical materials.