蔗糖 - 聚乙烯吡咯烷酮和蔗糖 - 山梨醇分散体系中的分子运动 - II. 退火对次级弛豫的影响

Molecular motions in sucrose-PVP and sucrose-sorbitol dispersions-II. Implications of annealing on secondary relaxations.

作者信息

Bhattacharya Sisir, Bhardwaj Sunny P, Suryanarayanan Raj

机构信息

Department of Pharmaceutics, University of Minnesota, Minneapolis, Minnesota, 55455, USA.

出版信息

Pharm Res. 2014 Oct;31(10):2822-8. doi: 10.1007/s11095-014-1379-2. Epub 2014 May 3.

DOI:10.1007/s11095-014-1379-2

PMID:24792829

Abstract

PURPOSE

To determine the effect of annealing on the two secondary relaxations in amorphous sucrose and in sucrose solid dispersions.

METHODS

Sucrose was co-lyophilized with either PVP or sorbitol, annealed for different time periods and analyzed by dielectric spectroscopy.

RESULTS

In an earlier investigation, we had documented the effect of PVP and sorbitol on the primary and the two secondary relaxations in amorphous sucrose solid dispersions (1). Here we investigated the effect of annealing on local motions, both in amorphous sucrose and in the dispersions. The average relaxation time of the local motion (irrespective of origin) in sucrose, decreased upon annealing. However, the heterogeneity in relaxation time distribution as well as the dielectric strength decreased only for β1- (the slower relaxation) but not for β2-relaxations. The effect of annealing on β2-relaxation times was neutralized by sorbitol while PVP negated the effect of annealing on both β1- and β2-relaxations.

CONCLUSIONS

An increase in local mobility of sucrose brought about by annealing could be negated with an additive.

摘要

目的

确定退火对无定形蔗糖及蔗糖固体分散体中两种次级弛豫的影响。

方法

将蔗糖与聚乙烯吡咯烷酮（PVP）或山梨醇共冻干，进行不同时间段的退火处理，并通过介电谱进行分析。

结果

在早期研究中，我们记录了PVP和山梨醇对无定形蔗糖固体分散体中初级弛豫及两种次级弛豫的影响（1）。在此，我们研究了退火对无定形蔗糖及其分散体中局部运动的影响。蔗糖中局部运动（无论其来源）的平均弛豫时间在退火后缩短。然而，弛豫时间分布的不均匀性以及介电强度仅在β1弛豫（较慢的弛豫）时降低，而β2弛豫时未降低。山梨醇抵消了退火对β2弛豫时间的影响，而PVP则消除了退火对β1和β2弛豫的影响。