caa a22 4500 445312130 CHVBK 20190416140711.0 cr unu---uuuuu 170323e20110901xx s 000 0 eng 10.1007/s11095-011-0447-0 doi (NATIONALLICENCE)springer-10.1007/s11095-011-0447-0 Molecular Motions in Sucrose-PVP and Sucrose-Sorbitol Dispersions: I. Implications of Global and Local Mobility on Stability [Elektronische Daten] [Sisir Bhattacharya, Raj Suryanarayanan] ABSTRACT: Purpose: To characterize molecular mobility by dielectric spectroscopy and determine the effect of additives on α- and β-relaxation times in amorphous sucrose solid dispersions. Methods: Sucrose was co-lyophilized with either PVP or sorbitol. The lyophiles were subjected to dielectric spectroscopy and differential scanning calorimetry. Results: The additives did not have an appreciable effect on the calorimetric Tg. However, dielectric spectroscopy revealed pronounced effects on global mobility (α-relaxation), which correlated with the crystallization tendency of sucrose. The systems were characterized by two β-relaxations, and the relaxation times as well as their temperature dependence were influenced by the additive. Although sorbitol acted as a plasticizer of sucrose with respect to global mobility, it anti-plasticized sucrose in terms of local motions. PVP, on the other hand, acted as an anti-plasticizer with respect to both global and local mobility. The slower β-relaxation in amorphous sucrose was found to correlate with the α-relaxation and was identified as the Johari-Goldstein relaxation. Conclusions: Amorphous systems with identical calorimetric Tg could have significantly different mobility and physical stability as revealed by dielectric spectroscopy. Additive effect on global mobility cannot be a predictor of the effects on local mobility. Additives could also be used to inhibit local mobility. Springer Science+Business Media, LLC, 2011 amorphous nationallicence dielectric spectroscopy nationallicence global and local mobility nationallicence solid dispersions nationallicence sucrose nationallicence Bhattacharya Sisir Department of Pharmaceutics, University of Minnesota, 55455, Minneapolis, Minnesota, USA aut Suryanarayanan Raj Department of Pharmaceutics, University of Minnesota, 55455, Minneapolis, Minnesota, USA aut Pharmaceutical Research Springer US; http://www.springer-ny.com 28/9(2011-09-01), 2191-2203 0724-8741 28:9<2191 2011 28 11095 https://doi.org/10.1007/s11095-011-0447-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11095-011-0447-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Bhattacharya Sisir Department of Pharmaceutics, University of Minnesota, 55455, Minneapolis, Minnesota, USA aut NATIONALLICENCE 700 1- Suryanarayanan Raj Department of Pharmaceutics, University of Minnesota, 55455, Minneapolis, Minnesota, USA aut NATIONALLICENCE 773 0- Pharmaceutical Research Springer US; http://www.springer-ny.com 28/9(2011-09-01), 2191-2203 0724-8741 28:9<2191 2011 28 11095 Metadata rights reserved Springer special CC-BY-NC licence nationallicence SWISSBIB 445312130 BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer