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XEDS-mapping for explaining release patterns from single pellets

Nevsten, Pernilla LU ; Borgquist, Per LU ; Axelsson, Anders LU and Wallenberg, Reine LU (2005) In International Journal of Pharmaceutics 290(1-2). p.109-120
Abstract
A common way to formulate controlled-release (CR) pharmaceuticals is to coat pellets of active substance with a polymer film, decrease the size of the pellets and distribute them as multiple-unit dosages in capsules. To increase the understanding of the release mechanism, the pellet shape and surface structure of pellets, before and after release in microtitre plates, have been studied by scanning electron microscope and X-ray energy-dispersive spectrometry. By performing these studies we associate release profiles during the first few hours to the microscopic structure. Pellets were divided into three classes (spherical pellets, dumbbell shaped pellets and twin-pellets) according to pellet form. Cases of burst release occurred for all... (More)
A common way to formulate controlled-release (CR) pharmaceuticals is to coat pellets of active substance with a polymer film, decrease the size of the pellets and distribute them as multiple-unit dosages in capsules. To increase the understanding of the release mechanism, the pellet shape and surface structure of pellets, before and after release in microtitre plates, have been studied by scanning electron microscope and X-ray energy-dispersive spectrometry. By performing these studies we associate release profiles during the first few hours to the microscopic structure. Pellets were divided into three classes (spherical pellets, dumbbell shaped pellets and twin-pellets) according to pellet form. Cases of burst release occurred for all three shape classes due to "open-window-defects" at the surface. Areas of thinner polymer film in the neck-region of dumbbell shaped pellets broaden the range of intermediate release rates for this pellet shape. The surface of twin pellets and dumbbell shaped pellets showed more defects, which increases the release rates in comparison to spherical pellets. All pellets with high release rates revealed ruptures in the polymer film, whereas only small cracks could be traced for pellets with slow release rates. The information gained is necessary for the development of future formulations and mathematical modelling of release patterns. The pharmaceutical used as model was remoxipride coated with a polymer film of ethyl cellulose and 10 wt.% triethyl citrate. (C) 2004 Elsevier B.V. All rights reserved. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
International Journal of Pharmaceutics
volume
290
issue
1-2
pages
109 - 120
publisher
Elsevier
external identifiers
  • wos:000226985500012
  • pmid:15664136
  • scopus:12344267897
ISSN
1873-3476
DOI
10.1016/j.ijpharm.2004.11.022
language
English
LU publication?
yes
id
e89298e3-0c68-4356-a8ee-0ceb0660cd5a (old id 151754)
date added to LUP
2007-06-25 13:38:00
date last changed
2017-01-01 04:53:47
@article{e89298e3-0c68-4356-a8ee-0ceb0660cd5a,
  abstract     = {A common way to formulate controlled-release (CR) pharmaceuticals is to coat pellets of active substance with a polymer film, decrease the size of the pellets and distribute them as multiple-unit dosages in capsules. To increase the understanding of the release mechanism, the pellet shape and surface structure of pellets, before and after release in microtitre plates, have been studied by scanning electron microscope and X-ray energy-dispersive spectrometry. By performing these studies we associate release profiles during the first few hours to the microscopic structure. Pellets were divided into three classes (spherical pellets, dumbbell shaped pellets and twin-pellets) according to pellet form. Cases of burst release occurred for all three shape classes due to "open-window-defects" at the surface. Areas of thinner polymer film in the neck-region of dumbbell shaped pellets broaden the range of intermediate release rates for this pellet shape. The surface of twin pellets and dumbbell shaped pellets showed more defects, which increases the release rates in comparison to spherical pellets. All pellets with high release rates revealed ruptures in the polymer film, whereas only small cracks could be traced for pellets with slow release rates. The information gained is necessary for the development of future formulations and mathematical modelling of release patterns. The pharmaceutical used as model was remoxipride coated with a polymer film of ethyl cellulose and 10 wt.% triethyl citrate. (C) 2004 Elsevier B.V. All rights reserved.},
  author       = {Nevsten, Pernilla and Borgquist, Per and Axelsson, Anders and Wallenberg, Reine},
  issn         = {1873-3476},
  language     = {eng},
  number       = {1-2},
  pages        = {109--120},
  publisher    = {Elsevier},
  series       = {International Journal of Pharmaceutics},
  title        = {XEDS-mapping for explaining release patterns from single pellets},
  url          = {http://dx.doi.org/10.1016/j.ijpharm.2004.11.022},
  volume       = {290},
  year         = {2005},
}