Synthesis and Characterization of Carboxymethylated Locust Bean Gum‐ co ‐poly(SA)‐ cl ‐poly(MBA) pH Responsive Hydrogel for Controlled Drug Delivery of Metformin Hydrochloride

Abstract The development of hydrophilic carriers with dual stimuli‐ responsiveness for the drug encapsulation and controlled release is one of the biggest challenges for the modern medicinal chemist. In this context, the current study explores the application of locust bean gum (LB), to develop a pH and temperature responsive matrix for controlled delivery of an anti‐diabetic drug, Metformin HCl (MFH) for the first time. LB gum was first structurally modified to carboxymethylated locust bean gum (CMLB). It was copolymerized with sodium acrylate (SA) and cross‐linked by using N,N‐methylene bisacrylamide (MBA) to form hydrogel (CMLB‐ co ‐poly(SA)‐ cl ‐poly(MBA)). The model hydrogel was examined using FTIR, TGA, SEM, XRD, and 13 C‐NMR to determine structural changes, thermal behaviour and surface morphology. Network parameters confirm the porous nature of the hydrogel and support their swelling behaviour. The drug loaded CMLB‐ co ‐poly(SA)‐ cl ‐poly(MBA) hydrogel follows the non‐Fickian diffusion of the anti‐diabetic drug, Metformin HCl (MFH), which is having short and biological half life time. The MFH release profile was analysed by fitting data in the Korsmeyer‐Peppas kinetic model with high rate of release in pH 7.4 compared to Distilled Water (DW) and pH 2.2. Thus we can explore the bio‐compatible synthesized hydrogel as a carrier for sustained drug delivery.