Water Clusters in Amorphous Pharmaceuticals

Low-Temperature Mobility of Water in Sugar Glasses: Insights from Thermally Stimulated Current Study

“…Water and sorbitol molecules are shown as blue and yellow objects, respectively. The Figure was published previously in Authelin et al (2014) the P1 event indicates all of the main signatures of dipole relaxation, i.e., linear response of the strength with voltage, and mirror image of signals obtained with +/À directions of the polarizing field (sucrose) and TSpC/TSdC (sorbitol). In addition, the fact that the P1 event was not detected in pure sorbitol (i.e., at 0 % water), and that the intensity of the signal was much lower in low water samples as compared with higher water samples in both sucrose-water and sorbitol-water systems, allows us to conclude that the origin of a P1 event is due to dielectric relaxation of water dipoles, probably because of the rotational mobility of water molecules, and that the temperature of the P1 event corresponds to the onset of dipole relaxation of water in sorbitol and sucrose glasses.…”

Counter-intuitive effect of non-crystallizing sugars on the crystallization of gemcitabine HCl in frozen solutions

“…Computer simulation studies of concentrated sugar-water solutions have also revealed the existence of such water clusters (Lerbret et al, 2005;Roberts and Debenedetti, 1999). This aspect has recently been reviewed by Authelin et al (2014).…”

Heterogeneity of Protein Environments in Frozen Solutions and in the Dried State

“…Inhomogeneity on the length scale of sub-nanometer to nanometer is a fundamental property of amorphous liquids (solutions), as summarized earlier [33]. Moreover, even a single-component system such as liquid water is nonhomogeneous on the molecular level, as illustrated by the Frank and Wen's model [53] (Fig.…”

“…In addition, we note that heterogeneity is a general property of solutions in both liquid and solid state (glasses). One specific case of heterogeneity was reviewed [33], where water clustering in solutions and amorphous solids was discussed as a probable case of heterogeneity on the sub-nanometer to nanometerlength scale. In the following two sections, we consider large-scale heterogeneities which are directly related to ice/solution interfaces.…”