Development and Characterization of Insulin-loaded Liposome-chitosan-Nanoparticle (LCS-NP) Complex and Investigation...

In recent years, studies on oral use have increased rapidly due to the restrictive aspects of parenteral administration of indispensable peptide-structured insulin in the rapidly growing worldwide treatment of diabetes. The aim of the study was to examine the development of a novel insulin-loaded LCS-NP complex, and its characterization and efficacy on pancreatic cells responsible for insulin release.

Blank liposomes and insulin-loaded LCS-NPs were prepared using dry film hydration and ionotropic gelation methods, respectively. The LCS-NP complex was prepared by mixing liposomes/NPs in a 2:1 (w/w) ratio. The cytotoxic effects of the various concentrations of insulin and formulation components on the pancreatic cell line were determined using a 3-(4,5-dimethyldiazol-2-yl)-2,5 diphenyl tetrazolium bromide assay and quantities to be used in the formulation were determined. Particle size, zeta potential, encapsulation efficiency, in vitro release profile and release kinetics, and transport properties of the prepared complex were investigated.

The newly developed insulin-loaded LCS-NP complex had a particle size of 2.85±0.035 μm and zeta potential of 8.11±1.025 mV. The encapsulation yield was found as 48±1.1%. In vitro insulin release from the complex was 80.9±2.71%. Insulin transport from β Tc cells was 30.50%. Permeability coefficients (log k) were calculated as -1.280±0.070 for the insulin solution and -1.020±0.062 for the insulin-loaded complex.

This study suggests that insulin could be successfully loaded into the newly developed LCS-NP complex, and it is thought that this complex carries an effective formulation potential for long-term efficacy in the treatment of diabetes.