Uptake and transport of insulin across intestinal membrane model using trimethyl chitosan coated insulin niosomes

This study reports the development of a highly stable niosomal nanostructure based on Span 60/cholesterol (CH)/N-trimethyl chitosan (TMC) system and its potential application for oral delivery of insulin. Insulin loaded niosomes were prepared by reversed-phase evaporation and TMC coating was performed by incubation of niosomal suspensions with TMC solution. The efficiency of nanoparticulate delivery system in enhancement of insulin permeation was evaluated by Caco-2 cell monolayer as intestinal membrane models. The prepared niosomes were characterized for entrapment efficiency (EE), particle size, zeta potential and stability. The particles were between 100 and 180 nm in diameter, and they were stable for over 60 days at 4 °C. Insulin permeability through Caco-2 cell monolayer was enhanced 4-fold by niosomal nanoparticles, compared with insulin alone. Further work is demanded to optimize this formulation with the object of maximizing its potential to facilitate oral delivery of insulin.