Ghatti gum-base graft copolymer: a plausible platform for pH-controlled delivery of antidiabetic drugs

Abstract

In the present study, we aimed to develop a novel pH-sensitive polymeric delivery system (GG-<i>g</i>-PMMA) for antidiabetic therapy <i>via</i> grafting ghatti gum (GG) with methyl methacrylate (MMA) chains. The free radical polymerization technique was adopted to graft ghatti gum with methyl methacrylate, using ceric ammonium nitrate (CAN) as a redox initiator. The impact on grafting parameters such as grafting percentage (<i>G</i>%) and grafting efficiency (GE), of monomer and initiator concentrations was evaluated. The batch with higher grafting efficiency and percentage grafting was selected and characterized by elemental analysis (C, H and N), DSC, FT-IR spectroscopy, XRD, ¹H-NMR and SEM morphology study. In addition, the efficacy of GG-<i>g</i>-PMMA-based pellets loaded with the hypoglycemic agent, metformin hydrochloride, to sustain drug release was investigated. <i>In vitro</i> release studies demonstrated a pH-dependent sustained release of the drug from GG-<i>g</i>-PMMA pellets. In addition, acute oral toxicity studies and histopathological analysis suggested the safety and biocompatibility of the grafted gum. Most importantly, <i>in vivo</i> efficacy studies underscored the efficient hypoglycemic potential of the prepared formulation, which was comparable to that of a sustained release marketed formulation. These results suggest that the developed pH-sensitive polymeric delivery system (GG-<i>g</i>-PMMA) might represent a promising delivery vehicle for facilitated antidiabetic therapy.