Solid state13C NMR investigation of impact of annealing in lyophilized glasses
Solid state13C NMR investigation of impact of annealing in lyophilized glasses
The purpose of this study was to investigate the impact of annealing on molecular mobility in lyophilized glasses, composed of a saccharide excipient and a small concentration of aspartame as a model “drug.” Changes in molecular dynamics during annealing were monitored through carbon (13C) T1 and T1? nuclear magnetic resonance relaxation times of the aspartame and the saccharides. Two different saccharides were studied, sucrose and trehalose. The local mobility of the aspartame guest was found to correlate closely with the overall structural relaxation monitored through calorimetric methods in the aspartame: sucrose formulation. In general terms, annealing leads to longer NMR relaxation times, indicating a slowing of the local dynamics. By contrast, annealing had only a minimal effect on the NMR relaxation times in aspartame: trehalose. Specificity of solid state NMR in detecting molecular mobility in guest and host molecules showed that sucrose provided a homogenous matrix for the guest drug as compared to the trehalose.
local dynamics, annealing, T1 relaxation time, T1? relaxation time, solid state nmr spectroscopy, amorphous state, molecular mobility, freeze drying/lyophilization
4336-4346
Luthra, Suman A.
eb6e4fd2-c867-47db-989a-45c8d6d56ac1
Pikal, Michael J.
f5e90147-e4bf-4bad-9386-6d7ceef7ee74
Utz, Marcel
c84ed64c-9e89-4051-af39-d401e423891b
October 2008
Luthra, Suman A.
eb6e4fd2-c867-47db-989a-45c8d6d56ac1
Pikal, Michael J.
f5e90147-e4bf-4bad-9386-6d7ceef7ee74
Utz, Marcel
c84ed64c-9e89-4051-af39-d401e423891b
Luthra, Suman A., Pikal, Michael J. and Utz, Marcel
(2008)
Solid state13C NMR investigation of impact of annealing in lyophilized glasses.
Journal of Pharmaceutical Sciences, 97 (10), .
(doi:10.1002/jps.21316).
(PMID:18240306)
Abstract
The purpose of this study was to investigate the impact of annealing on molecular mobility in lyophilized glasses, composed of a saccharide excipient and a small concentration of aspartame as a model “drug.” Changes in molecular dynamics during annealing were monitored through carbon (13C) T1 and T1? nuclear magnetic resonance relaxation times of the aspartame and the saccharides. Two different saccharides were studied, sucrose and trehalose. The local mobility of the aspartame guest was found to correlate closely with the overall structural relaxation monitored through calorimetric methods in the aspartame: sucrose formulation. In general terms, annealing leads to longer NMR relaxation times, indicating a slowing of the local dynamics. By contrast, annealing had only a minimal effect on the NMR relaxation times in aspartame: trehalose. Specificity of solid state NMR in detecting molecular mobility in guest and host molecules showed that sucrose provided a homogenous matrix for the guest drug as compared to the trehalose.
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e-pub ahead of print date: 31 January 2008
Published date: October 2008
Keywords:
local dynamics, annealing, T1 relaxation time, T1? relaxation time, solid state nmr spectroscopy, amorphous state, molecular mobility, freeze drying/lyophilization
Organisations:
Magnetic Resonance
Identifiers
Local EPrints ID: 354827
URI: http://eprints.soton.ac.uk/id/eprint/354827
ISSN: 0022-3549
PURE UUID: f039890d-69b3-4c70-a12f-8c5871e32eca
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Date deposited: 23 Jul 2013 12:05
Last modified: 15 Mar 2024 03:44
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Author:
Suman A. Luthra
Author:
Michael J. Pikal
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