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Development of mass transport resistance in poly(lactide-co-glycolide) films and particles - A mechanistic study.

Fredenberg, Susanne LU ; Jönsson, Monica; Laakso, Timo; Wahlgren, Marie LU ; Reslow, Mats and Axelsson, Anders LU (2011) In International Journal of Pharmaceutics 409(1-2). p.194-202
Abstract
Poly(d,l-lactide-co-glycolide) (PLG) is the most frequently used biodegradable polymer in the controlled release of an encapsulated drug. The purpose of this work was to explain the surprisingly slow diffusion through this polymer, and locate the major source of mass transport resistance. Diffusion of human growth hormone (hGH) and glucose through PLG films was undetectable (using a diffusion cell), although the degraded polymer contained several times more water than polymer mass. In vitro release of hGH from PLG-coated particles also showed a surprisingly slow rate of release. Non-porous regions inside the PLG films were detected after three weeks of degradation using dextran-coupled fluorescent probes and confocal microscopy. The... (More)
Poly(d,l-lactide-co-glycolide) (PLG) is the most frequently used biodegradable polymer in the controlled release of an encapsulated drug. The purpose of this work was to explain the surprisingly slow diffusion through this polymer, and locate the major source of mass transport resistance. Diffusion of human growth hormone (hGH) and glucose through PLG films was undetectable (using a diffusion cell), although the degraded polymer contained several times more water than polymer mass. In vitro release of hGH from PLG-coated particles also showed a surprisingly slow rate of release. Non-porous regions inside the PLG films were detected after three weeks of degradation using dextran-coupled fluorescent probes and confocal microscopy. The findings were supported by scanning electron microscopy. Diffusion through PLG films degraded for five weeks was significantly increased when the porosity of both surfaces was increased due to the presence of ZnCl(2) in the buffer the last 3 days of the degradation period. The results indicated high mass transport resistance inside the films after three weeks of degradation, and at the surfaces after five weeks of degradation. These results should also be applicable to microparticles of different sizes. Knowledge of the reason for transport resistance is important in the development of pharmaceuticals and when modifying the rate of drug release. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
International Journal of Pharmaceutics
volume
409
issue
1-2
pages
194 - 202
publisher
Elsevier
external identifiers
  • wos:000290135800024
  • pmid:21392561
  • scopus:79955008446
ISSN
1873-3476
DOI
10.1016/j.ijpharm.2011.02.066
language
English
LU publication?
yes
id
c2a219b4-f331-41e7-8b80-5b465ac3fdef (old id 1884092)
date added to LUP
2011-04-20 08:58:57
date last changed
2017-01-01 03:33:04
@article{c2a219b4-f331-41e7-8b80-5b465ac3fdef,
  abstract     = {Poly(d,l-lactide-co-glycolide) (PLG) is the most frequently used biodegradable polymer in the controlled release of an encapsulated drug. The purpose of this work was to explain the surprisingly slow diffusion through this polymer, and locate the major source of mass transport resistance. Diffusion of human growth hormone (hGH) and glucose through PLG films was undetectable (using a diffusion cell), although the degraded polymer contained several times more water than polymer mass. In vitro release of hGH from PLG-coated particles also showed a surprisingly slow rate of release. Non-porous regions inside the PLG films were detected after three weeks of degradation using dextran-coupled fluorescent probes and confocal microscopy. The findings were supported by scanning electron microscopy. Diffusion through PLG films degraded for five weeks was significantly increased when the porosity of both surfaces was increased due to the presence of ZnCl(2) in the buffer the last 3 days of the degradation period. The results indicated high mass transport resistance inside the films after three weeks of degradation, and at the surfaces after five weeks of degradation. These results should also be applicable to microparticles of different sizes. Knowledge of the reason for transport resistance is important in the development of pharmaceuticals and when modifying the rate of drug release.},
  author       = {Fredenberg, Susanne and Jönsson, Monica and Laakso, Timo and Wahlgren, Marie and Reslow, Mats and Axelsson, Anders},
  issn         = {1873-3476},
  language     = {eng},
  number       = {1-2},
  pages        = {194--202},
  publisher    = {Elsevier},
  series       = {International Journal of Pharmaceutics},
  title        = {Development of mass transport resistance in poly(lactide-co-glycolide) films and particles - A mechanistic study.},
  url          = {http://dx.doi.org/10.1016/j.ijpharm.2011.02.066},
  volume       = {409},
  year         = {2011},
}