(493n) Laboratory SWAXS for Applications in Pharmaceutical Technology

Combined small- and wide-angle X-ray scattering (SWAXS) is becoming an increasingly important technique in pharmaceutical solid-state characterization1). Highly relevant questions of polymorphism in crystalline materials, stability and nanostructure of amorphous states, inner surface in controlled-release formulations, and stability and ageing of controlled release formulations can be addressed by this technique. The information to be gained by SAXS expands largely the scope of conventional powder diffraction techniques. A particular advantage lies in the simultaneous observation of nano-scale (SAXS) and atomic scale (WAXS). With the development of high-brilliance laboratory SWAXS systems (Hecus S3MICROpix) the times for analysis have been greatly reduced, and hence the method can be applied to quality screening and process analytical technology (PAT). Examples will be presented for technologically relevant systems, such as polymorphic forms of active ingredients (carbamazepine) and amorphous formulations. The results show, that an analysis in terms of robust SAXS parameters, such as inner surface, total absolute scattering power, and Porod exponent, can provide highly valuable technological information.

Reference

1) Laggner, P., M. Kriechbaum, M. Rappolt, G. Pabst, H. Amenitsch, A. Johs, K. Lohner, D. Zweytick, R. Koschuch, and P. Abuja. 2005. Pharmaceutical solid-state characterization by small-and wide-angle x-ray scattering, In: Solid State Characterization of Pharmaceuticals. Eds. A. and M. Zakrzewski. Assa International, Danbury, chapter 12.