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Determination of the release mechanism of Theophylline from pellets coated with Surelease (R)-A water dispersion of ethyl cellulose

Jurgita Kazlauske (Institutionen för kemi och kemiteknik, Farmaceutisk teknologi ; SuMo Biomaterials) ; M. M. Cafaro ; D. Caccavo ; M. Marucci ; G. Lamberti ; A. A. Barba ; Anette Larsson (Institutionen för kemi och kemiteknik, Farmaceutisk teknologi ; SuMo Biomaterials)
International Journal of Pharmaceutics (0378-5173). Vol. 528 (2017), 1-2, p. 345-353.
[Artikel, refereegranskad vetenskaplig]

The aim of this study was to investigate the water transport over free standing films based on the aqueous ethyl cellulose (EC) coating Surelease (R) and the drug (Theophylline) release mechanism from coated pellets. It was found that the main drug release rate from pellets was controlled by a diffusion mechanism. However, the drug release rate was altered by addition of sodium chloride to the external release medium. A decrease in the drug release rate when sodium chloride is added to the release medium has traditionally been used to indicate an osmotic drug release mechanism. However, our findings that the release rate decreased by sodium chloride addition could be explained by sodium chloride diffusing through the coating layer into the inner parts of the pellets, decreasing the solubility of Theophylline. This gave a reduced drug concentration gradient over the coating layer and thus a slower release rate. Furthermore, this study shows, as expected, that the transport of water through Surelease (R) films into the pellets was faster than the transport out of Theophylline (approx. seven times), which was the reason why the pellets were swelling during the release. It was also shown that the drug release rate, determined for both whole dose release and for single pellets, decreased with increasing thickness (from 16 to 51 mm) of the coating layer controlling the drug release rate.

Nyckelord: Controlled drug release, Coated pellets, Aqueous based coating, Ethyl cellulose, Surelease (R),Molecular-Weight, Film Coatings, Polymer-Films, Ethylcellulose, Delivery, Permeability, Plasticizers, Stability, Colon



Denna post skapades 2017-09-14.
CPL Pubid: 251881

 

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Institutioner (Chalmers)

Institutionen för kemi och kemiteknik, Farmaceutisk teknologi
SuMo Biomaterials

Ämnesområden

Farmaceutisk kemi

Chalmers infrastruktur