pH Responsive Polymeric Nanoparticles for Oral Insulin Delivery

Gelatin-eudragit L100 nanoparticles of wet size range 170-563nm were prepared by two step dissolvation method and the effect of different concentrations of eudragit L100 and emulsifying agent - sodium lauryl sulphate (SLS) - on the particle size were studied. Synthesized nanoparticles were characterized by attenuated total reflectance-fourier transform infrared spectroscopy (ATRFTIR) and the mean size distribution. Insulin loading was done at a pH 7.4 and the in vitro insulin release studies of nanoparticles were carried out by simulating gastrointestinal tract condition which showed the minimal insulin release at pH 2.5 (20% in 90min) while appreciable release (40% in first 30min) at pH of 7.4. This pH responsive release pattern of the synthesized nanoparticles confers on the insulin protection from proteolytic degradation in acidic environment of stomach and upper intestinal part while enhancing bioavailability in the later part of intestine.