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Pore formation and pore closure in Poly(D,L-lactide-co-glycolide) films.

Fredenberg, Susanne LU ; Wahlgren, Marie LU ; Reslow, Mats and Axelsson, Anders LU (2011) In Journal of Controlled Release 150. p.142-149
Abstract
Pore formation and pore closure in poly(D,L-lactide-co-glycolide)-based drug delivery systems are two important processes as they control the release of the encapsulated drug. The phenomenon pore closure was investigated by studying the effects of the pH and the temperature of the release medium, and the properties of the polymer. Poly(D,L-lactide-co-glycolide) (PLG) films were subjected to a pore forming pre-treatment, and then pore closure was observed simultaneously with changes in glass transition temperature, wettability (contact angle), water absorption and mass remaining. To further understand the effect of pH, combined pore formation and pore closure were studied at different pH values. Pore closure was increased in a release... (More)
Pore formation and pore closure in poly(D,L-lactide-co-glycolide)-based drug delivery systems are two important processes as they control the release of the encapsulated drug. The phenomenon pore closure was investigated by studying the effects of the pH and the temperature of the release medium, and the properties of the polymer. Poly(D,L-lactide-co-glycolide) (PLG) films were subjected to a pore forming pre-treatment, and then pore closure was observed simultaneously with changes in glass transition temperature, wettability (contact angle), water absorption and mass remaining. To further understand the effect of pH, combined pore formation and pore closure were studied at different pH values. Pore closure was increased in a release medium with low pH, with a low-molecular-weight PLG of relatively low degree of hydrophobicity, or at high temperature. Pore closure occurred by two different mechanisms, one based on polymer-polymer interactions and one on polymer-water interactions. The mobility of the PLG chains also played an important role. The surface of the PLG films were more porous at pH 5-6 than at lower or higher pH, as pore formation was relatively fast and pore closure were less pronounced in this pH range. The pH had a significant impact on the porous structure, which should be kept in mind when evaluating experimental results, as the pH may be significantly decreased in vitro, in vivo and in situ. The results also show that the initial porosity is very important when using a high-molecular-weight PLG. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Controlled Release
volume
150
pages
142 - 149
publisher
Elsevier
external identifiers
  • wos:000289701200003
  • pmid:21094192
  • scopus:79952992027
ISSN
1873-4995
DOI
10.1016/j.jconrel.2010.11.020
language
English
LU publication?
yes
id
2c858323-a53d-4676-85a4-16560ca64f3f (old id 1731726)
date added to LUP
2010-12-15 12:26:29
date last changed
2017-08-13 03:08:58
@article{2c858323-a53d-4676-85a4-16560ca64f3f,
  abstract     = {Pore formation and pore closure in poly(D,L-lactide-co-glycolide)-based drug delivery systems are two important processes as they control the release of the encapsulated drug. The phenomenon pore closure was investigated by studying the effects of the pH and the temperature of the release medium, and the properties of the polymer. Poly(D,L-lactide-co-glycolide) (PLG) films were subjected to a pore forming pre-treatment, and then pore closure was observed simultaneously with changes in glass transition temperature, wettability (contact angle), water absorption and mass remaining. To further understand the effect of pH, combined pore formation and pore closure were studied at different pH values. Pore closure was increased in a release medium with low pH, with a low-molecular-weight PLG of relatively low degree of hydrophobicity, or at high temperature. Pore closure occurred by two different mechanisms, one based on polymer-polymer interactions and one on polymer-water interactions. The mobility of the PLG chains also played an important role. The surface of the PLG films were more porous at pH 5-6 than at lower or higher pH, as pore formation was relatively fast and pore closure were less pronounced in this pH range. The pH had a significant impact on the porous structure, which should be kept in mind when evaluating experimental results, as the pH may be significantly decreased in vitro, in vivo and in situ. The results also show that the initial porosity is very important when using a high-molecular-weight PLG.},
  author       = {Fredenberg, Susanne and Wahlgren, Marie and Reslow, Mats and Axelsson, Anders},
  issn         = {1873-4995},
  language     = {eng},
  pages        = {142--149},
  publisher    = {Elsevier},
  series       = {Journal of Controlled Release},
  title        = {Pore formation and pore closure in Poly(D,L-lactide-co-glycolide) films.},
  url          = {http://dx.doi.org/10.1016/j.jconrel.2010.11.020},
  volume       = {150},
  year         = {2011},
}