oral delivery of insulin from trimethyl chitosan/tragacanth: in vitro, mtt, and in vivo bioactivity tests

Insulin-loaded trimethyl chitosan (tmc)/tragacanth microspheres were prepared by microemulsion dispersion and triggered in situ gelation. microspheres were characterized by their mean size and distribution by laser diffraction spectroscopy and brunauer-emmet-teller theory. insulin encapsulation efficiency and in vitro release were determined by bradford protein assay, and bioactivity was assessed in vitro using an enzyme-linked immunoassay diagnostic kit and in vivo using wistar diabetic rats. tmc/tragacanth particles suppressed insulin release in acidic media and promoted a sustained release at near-neutral conditions. micro-capsulated insulin was bioactive, demonstrated by both in vivo and in vitro bioassays.