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The role of space charge formation in the generation of thermally stimulated current (TSC) spectroscopy data for a model amorphous drug system

Antonijević, M.D., Craig, D.Q.M., Barker, S.A. (2008) The role of space charge formation in the generation of thermally stimulated current (TSC) spectroscopy data for a model amorphous drug system. International Journal of Pharmaceutics, 353 (1-2). pp. 8-14. ISSN 0378-5173. (doi:10.1016/j.ijpharm.2007.11.004) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided) (KAR id:78859)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided. (Contact us about this Publication)
Official URL
https://doi.org/10.1016/j.ijpharm.2007.11.004

Abstract

Thermally stimulated current (TSC) spectroscopy is attracting increasing attention as a means of materials characterization, particularly in terms of measuring slow relaxation processes in solid samples. However, wider use of the technique within the pharmaceutical field has been inhibited by difficulties associated with the interpretation of TSC data, particularly in terms of deconvoluting dipolar relaxation processes from charge distribution phenomena. Here, we present evidence that space charge and electrode contact effects may play a significant role in the generation of peaks that have thus far proved difficult to interpret. We also introduce the use of a stabilization temperature in order to control the space charge magnitude. We have studied amorphous indometacin as a model drug compound and have varied the measurement parameters (stabilization and polarization temperatures), interpreting the changes in spectral composition in terms of charge redistribution processes. More specifically, we suggested that charge drift and diffusion processes, charge injection from the electrodes and high activation energy charge redistribution processes may all contribute to the appearance of shoulders and 'spurious' peaks. We present recommendations for eliminating or reducing these effects that may allow more confident interpretation of TSC data.

Item Type: Article
DOI/Identification number: 10.1016/j.ijpharm.2007.11.004
Uncontrolled keywords: Amorphous, Depletion region, Dielectric, Pharmaceutical, Space charge, Thermally stimulated current, indometacin, article, calculation, diffusion, drug determination, electrode, energy, priority journal, spectroscopy, temperature, thermal stimulation, thermally stimulated current spectroscopy, Chemistry, Pharmaceutical, Electrodes, Indomethacin, Spectrum Analysis, Technology, Pharmaceutical
Divisions: Faculties > Sciences > Medway School of Pharmacy
Depositing User: Susan Barker
Date Deposited: 27 Nov 2019 11:06 UTC
Last Modified: 27 Nov 2019 11:06 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/78859 (The current URI for this page, for reference purposes)
Barker, S.A.: https://orcid.org/0000-0003-4880-0253
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