Novel insulin-montmorillonite sodium complex containing pH regulated nanocomposite hydrogels

Abstract

Main objective of current work was to develop pH responsive polymeric systems for safe oral delivery of insulin. A novel fenugreek seed mucilage extract-based pH-regulated hydrogel (FA) system by free radical polymerization. Insulin was directly post-loaded in developed hydrogels (I-FA) as well as in the form of insulin-montmorillonite-Na + complexes (I-MT) to prepare nanocomposite (NC) hydrogels (I-MT-FA). Both I-FA and I-MT-FA NC hydrogels were subjected to FTIR, PXRD, EDX, SEM, DSC, and TGA studies. FTIR, PXRD, and EDX results validated the safe incorporation of insulin in both formulation types. SEM photomicrographs showed variable surface morphology. Thermal studies ensured the higher thermal stability of I-MT-FA NC hydrogels. Gel fraction (%) analysis, swelling studies (%), and in-vitro release studies (%) were also performed. In-vivo pharmacodynamics and pharmacokinetics evaluations of the two optimized formulations (I-FA6 hydrogel and I-MT-FA6 NC hydrogel) showed relative bioavailability of 26.15 times for I-FA hydrogel and 50.65 times for I-MT-FA6 NC hydrogels against oral insulin solution. Acute oral toxicity studies ensured the safety and biocompatibility of developed networks among research animals.