Format

Send to

Choose Destination
See comment in PubMed Commons below
Int J Pharm. 2000 Aug 10;203(1-2):89-98.

Characterization of thermosensitive chitosan gels for the sustained delivery of drugs.

Author information

  • 1Faculty of Pharmacy, University of Montreal, PO Box 6128 succ. Centre-Ville, Quebec, H3C 3J7, Montreal, Canada.

Abstract

The aim of this study was to investigate the physical properties of a chitosan/glycerophosphate (GP) thermosensitive solution which gels at 37 degrees C and evaluate the in vitro release profiles of different model compounds. The gelation rate was dependent on the temperature and on the chitosan deacetylation degree. The solution containing 84%-deacetylated chitosan could be stored 3 months at 4 degrees C without apparent change in viscosity. The in vitro release profiles of the model compounds depended on the presence of GP in the chitosan solution, on their molecular weight and on the presence of lysozyme in the release media. They were not affected by the electrostatic charge of the model compound when present at low concentrations. During the first 4 h, the release was accompanied by a substantial loss of the gel weight which was mainly attributed to the leaching of water and excess GP. Scanning electron micrographs revealed that the solutions yield gels with a highly porous structure after 24 h of exposure to a continuous flow of phosphate buffered saline. These results indicate that the chitosan/GP thermosensitive solutions gel rapidly at body temperature, can remain in the sol state at 4 degrees C and can sustain the delivery of macromolecules.

PMID:
10967431
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Write to the Help Desk