The Glass Transition and Sub-Tg-Relaxation in Pharmaceutical Powders and Dried Proteins by Thermally Stimulated Current

Local Mobility in Amorphous Pharmaceuticals—Characterization and Implications on Stability

“…112 The other related, less frequently used technique is the thermally stimulated polarization current (TSPC) which consists of application of an electric field at a low temperature where dipole mobility is restricted, followed by polarization of the dipoles during heating. 113 Compared to TSDC, TSPC has the advantage of probing a material with minimal effect on its thermal history and has been used to characterize local motions in pharmaceutical macromolecules. 113 …”

“…113 Compared to TSDC, TSPC has the advantage of probing a material with minimal effect on its thermal history and has been used to characterize local motions in pharmaceutical macromolecules. 113 …”

Mechanisms of protein stabilization in the solid state

“…Recently there is strong interest in an alternate thermal analysis technique called thermally stimulated current (TSC). [93][94][95] Since obtaining T g using TSC does not depend on DC p of the glass because it responds to the mobility of dipoles and other permanent or induced electric charges in a glass matrix, this technique has an advantage, which is potentially very useful in detecting the T g of pure proteins. 94 In addition, T g , DT g , and DC p for ''pure'' human growth hormone (hGH) were evaluated by extrapolating the thermal analysis data in protein: disaccharide mixtures, and it was found that DT g is indeed large and DC p is indeed small for the protein.…”

“…[93][94][95] Since obtaining T g using TSC does not depend on DC p of the glass because it responds to the mobility of dipoles and other permanent or induced electric charges in a glass matrix, this technique has an advantage, which is potentially very useful in detecting the T g of pure proteins. 94 In addition, T g , DT g , and DC p for ''pure'' human growth hormone (hGH) were evaluated by extrapolating the thermal analysis data in protein: disaccharide mixtures, and it was found that DT g is indeed large and DC p is indeed small for the protein. 26 Since a fragile glass exhibits non-Arrhenius behavior of relaxation time, the plot of log t as a function of T g /T exhibits curvature for a fragile glass but essentially linear behavior for a strong glass above but near T g .…”

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

“…In addition, we probed whether similar behavior can be expected in other polyhydroxy compounds by using sorbitol, a sugar alcohol. TSC is a thermal analytical technique that has been used to study dipole relaxation in different types of materials, including synthetic polymers, small molecular-weight glass-formers, and proteins (Teyssedre et al 1995;Fagegaltier et al 1997;Correia et al 2000;Galop and Collins 2001;Shmeis et al 2004;Reddy et al 2009). In addition, TSC has been used to study low-temperature molecular mobility in aqueous sugar solutions and hexagonal ice (Johari and Jones 1975;Apekis et al 1983).…”