Concomitant dehydration mechanisms in single crystals of α,α-trehalose

The dehydration behaviour of α,α-trehalose (α-d-glucopyranosyl α-d-glucopyranoside) dihydrate single crystals is investigated by thermomicroscopy, Raman microscopy, and differential scanning calorimetry. The results show at a given stage the simultaneous presence of two polymorphic forms, amorphous material, and movement of a fluid phase. The study also underlines that the characterization of the average phase by conventional XRPD and DSC techniques is not sufficient to describe the dehydration mechanisms of α,α-trehalose particles. Moreover, it confirms that the dehydration behaviour is mainly driven by heterogeneities and the rate of water loss.

Graphical abstractCoexistence of three trehalose phases (TRE-h, TRE-am and TRE-β) in the same crystal at ambient temperature.Figure optionsDownload full-size imageDownload as PowerPoint slide