Investigation of preparation methods on surface/bulk structural relaxation and glass fragility of amorphous solid dispersions

Ke, P., Hasegawa, S., Al-Obaidi, H. and Buckton, G. (2012) Investigation of preparation methods on surface/bulk structural relaxation and glass fragility of amorphous solid dispersions. International Journal of Pharmaceutics, 422 (1-2). p. 170. 10.1016/j.ijpharm.2011.10.047.

Full text not available from this repository.

DOI: 10.1016/j.ijpharm.2011.10.047

Abstract

The objective of this study was to investigate the effect of preparation methods on the surface/bulk molecular mobility and glass fragility of solid dispersions. Solid dispersions containing indometacin and PVP K30 were chosen as the model system. An inverse gas chromatography method was used to determine the surface structural relaxation of the solid dispersions and these data were compared to those for bulk relaxation obtained by DSC. The values of τβ for the surface relaxation were 4.6, 7.1 and 1.8 h for melt quenched, ball milled and spray dried solid dispersions respectively, compared to 15.6, 7.9 and 9.8 h of the bulk. In all systems, the surface had higher molecular mobility than the bulk. The glass fragility of the solid dispersions was also influenced by the preparation methods with the most fragile system showing the best stability. The zero mobility temperature (T 0) was used to correlate with the physical stability of the solid dispersions. Despite having similar Tg (65°C), the T0 of the melt quenched, ball milled and spray dried samples were 21.6, -4.2 and 16.7°C respectively which correlated well with their physical stability results. Therefore, T0 appears to be a better indicator than T g for predicting stability of amorphous materials.

Item Type:Article
Uncontrolled Keywords:Amorphous solid dispersion; Glass fragility; Inverse gas chromatography; Stability; Structural relaxation; Zero mobility temperature
Departments, units and centres:Department of Pharmaceutics > Department of Pharmaceutics
ID Code:2791
Journal or Publication Title:International Journal of Pharmaceutics
Deposited By:Library Staff
Deposited On:10 Feb 2012 10:44
Last Modified:10 Feb 2012 10:44

Repository Staff Only: Item control page

School of Pharmacy Staff Only: Edit a copy to replace this item