Effects of interpenetration of thermo-sensitive gels by crosslinking of chitosan on nasal delivery of insulin: In vitro characterization and in vivo study

Tze Wen Chung, Der Zen Liu, Juin Sen Yang

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28 Citations (Scopus)


This investigation examines the in vitro release of insulin in new thermo-response P-CS/GA/Gly gels, in which a chitosan (CS), crosslinked using glutaraldehyde (GA), interpenetrates Poloxamer (P) gels, and glycine (Gly) is further added to inhibit the crosslinking reactions of GA. The delivery of insulin by nasally administering P-CS/GA/Gly gels in diabetic rats was also examined. The release of insulin from P-CS/GA/Gly gels was significantly sustained (P <0.01) for about six times longer than release from P gels. The mechanisms of the release of insulin from the gels were consistent with a Fickian diffusion model. The nasal administering of insulin using P-CS/GA/Gly gels in diabetic rats is associated with a greatly prolonged hyperglycemic effect and a pharmacological efficiency (involving the maintenance of the lowest possible blood glucose levels (Cmin, 55.5 ± 2.8% of original values, n = 6) for 3 h, with a pharmacological efficiency of 18.0 ± 1.8% (n = 6)) that significantly exceeded those achieved using other gels.

Original languageEnglish
Pages (from-to)316-322
Number of pages7
JournalCarbohydrate Polymers
Issue number2
Publication statusPublished - Sep 5 2010



  • Chitosan
  • Crosslinking
  • Insulin delivery
  • Nasal drug delivery
  • Poloxamer gel
  • Sustained release

ASJC Scopus subject areas

  • Organic Chemistry
  • Materials Chemistry
  • Polymers and Plastics

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