SEMINAR ANNOUNCEMENT

PhD Thesis Defence Seminar
Chitosan nanoparticles for the oral delivery of insulin

by

Mr Ma Zengshuan
Department of Pharmacy
National University of Singapore

on

Date: Tuesday, 20May 2003
Time: 1000 - 1100 hrs
Venue: S4-05-10

Synopsis:

Chitosan-insulin nanoparticles were prepared by ionotropic gelation of chitosan with tripolyphosphate anions. pH was found an important factor to determine the characteristics of nanoparticles, including particle size, zeta potential, association efficiency (AE), loading efficiency and release profiles in various media. The oral efficacy of two formulations with AE of 39.6% and 82.9% was compared to insulin solution in streptozotocin-induced diabetic rats after oral administration. They showed a marked dose-dependent hypoglycemic response that had a delayed onset and sustained duration. Covalent conjugation with FITC yielded fluorescent chitosan molecules, which could be formulated into labeled nanoparticles and enabled the cellular uptake of chitosan nanoparticles and molecules to be quantified by fluorimetry. The formation of nanoparticles could significantly promote the uptake of chitosan in Caco-2 cell monolayers. The uptake of chitosan nanoparticles was time-, concentration-, and temperature-dependent.

Keywords: chitosan, insulin, nanoparticles, in vitro release, in vivo efficacy, uptake

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