Insulin nanoparticles for transdermal delivery: preparation and physicochemical characterization and in vitro evaluation

Aim: This work is aimed to study the feasibility of insulin nanoparticles for transdermal drug delivery (TDD) using supercritical antisolvent (SAS) micronization process. Methods: The influences of various experimental factors on the mean particle size (MPS) of insulin nanoparticles were investigated. Moreover, the insulin nanoparticles obtained were characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and thermogravimetric (TG) analyses. Results: Under optimum conditions, uniform spherical insulin nanoparticles with a MPS of 68.2 ± 10.8 nm were obtained. The Physicochemical characterization results showed that SAS process has not induced degradation of insulin. Evaluation in vitro showed that insulin nanoparticles were accorded with the Fick's first diffusion law and had a high permeation rate. Conclusion: These results suggest that insulin nanoparticles can have a great potential in TDD systems of diabetes chemotherapy.