Ryan, Eimear M. and Breslin, Carmel B.
(2018)
Formation of polypyrrole with dexamethasone as a dopant: Its cation and anion exchange properties.
Journal of Electroanalytical Chemistry, 824.
pp. 188-194.
ISSN 1572-6657
Abstract
There is considerable interest in dexamethasone, a synthetic glucocorticosteroid drug, and a number of reports
detailing the controlled release of dexamethasone from polypyrrole have been published. However, polypyrroledoped with dexamethasone is poorly characterised. In this study, polypyrrole doped with dexamethasone was
formed at relatively low applied potentials of 0.70 V or 0.80 V vs SCE by carrying out the electropolymerisation
on an initial pre-layer of polypyrrole. These polymers displayed electroactive behaviour with a dexamethasone
doping level of 0.30 ± 0.03 and using impedance measurements the charge-transfer resistance was computed as
400 Ω. Mixed ion transport was observed. In addition to the release of dexamethasone, hydrated sodium cations
were incorporated to maintain charge neutrality on reduction of the polymer. Approximately 200 μg cm−2 of
dexamethasone was released following 60 min on reduction of the polymer at −0.90 V vs SCE. It was possible to
re-use the polymer to release the drug by repeated oxidation and reduction steps, where dexamethasone was
incorporated during oxidation and released on reduction. During these events, sodium was accumulated within
the polymer matrix and this high salt content accompanied with swelling and de-swelling events gave rise to the
development of cracks in the polymer matrix.
| Item Type: |
Article
|
| Keywords: |
Polypyrrole;
Dexamethasone;
Electropolymerisation;
Sodium accumulation;
Mixed ion exchange; |
| Academic Unit: |
Faculty of Science and Engineering > Chemistry |
| Item ID: |
13121 |
| Identification Number: |
https://doi.org/10.1016/j.jelechem.2018.07.052 |
| Depositing User: |
Dr. Carmel Breslin
|
| Date Deposited: |
20 Jul 2020 15:54 |
| Journal or Publication Title: |
Journal of Electroanalytical Chemistry |
| Publisher: |
Elsevier |
| Refereed: |
Yes |
| URI: |
|
| Use Licence: |
This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available
here |
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