Dielectric Studies on Molecular Dynamics of Two Important Disaccharides: Sucrose and Trehalose

被引：24

作者：

Kaminski, K. ^{[1
]}

Adrjanowicz, K. ^{[1
]}

Zakowiecki, D. ^{[2
]}

Kaminska, E. ^{[3
]}

Wlodarczyk, P. ^{[1
]}

Paluch, M. ^{[1
]}

Pilch, J. ^{[4
]}

Tarnacka, M. ^{[1
]}

机构：

[1] Univ Silesia, Inst Phys, PL-40007 Katowice, Poland

[2] Pharmaceut Works Polpharma SA, Preformulat Dept R&D, PL-83200 Starogard Gdanski, Poland

[3] Med Univ Silesia, Dept Pharmacognosy & Phytochem, PL-41200 Sosnowiec, Poland

[4] Acad Phys Educ, Dept Biol Sci, PL-40074 Katowice, Poland

来源：

MOLECULAR PHARMACEUTICS | 2012年 / 9卷 / 06期

关键词：

glass transition; disaccharides; molecular dynamics; dielectric spectroscopy; dc conductivity; primary and secondary relaxations; GLASS-TRANSITION; PHARMACEUTICAL SYSTEMS; SECONDARY RELAXATION; AMORPHOUS SUCROSE; TEMPERATURE RANGE; BETA-RELAXATION; C-13; NMR; MOBILITY; WATER; POLYSACCHARIDES;

D O I：

10.1021/mp2004498

中图分类号：

R-3 [医学研究方法]; R3 [基础医学];

学科分类号：

1001 ;

摘要：

Broadband dielectric measurements were carried out in the supercooled as well as in the glassy state of two very important disaccharides: trehalose and sucrose. Multiple relaxation processes were observed. Above the glass transition temperatures of examined disaccharides structural relaxation of cooperative origin was detected, where in the glassy state more local motions (secondary modes) appeared. Our data were discussed in light of the findings reported by other groups. We pointed out that sample preparation might impact mobility and, thus, dielectric loss spectra in a significant way. Consequently, it may lead to misinterpretation of the dielectric relaxation processes. Moreover, impact of physical aging and pressure on dynamics of two secondary relaxation processes observed in the glassy state of trehalose and sucrose has been investigated. Additionally, we have demonstrated that, in contrast to the calorimetric measurements (DSC), activation energies of the beta- and gamma-relaxation processes observed in the glassy state of sucrose and trehalose do not change as a result of physical aging. Finally, we found out that the beta-relaxation process slows down as pressure increases. We interpreted this fact in view of increasing rigidity of the structures of disaccharides.

引用

页码：1559 / 1569

页数：11

共 67 条

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