Synthesis and characterization of novel xanthan gum-based pH-sensitive hydrogel for metformin hydrochloride release

In the current study, the synthesis of hydrogel based on carboxymethyl tamarind kernel gum (CMTKG), poly(sodium acrylate) (PSA), xanthan gum (XG) and its loading with metformin hydrochloride (metformin HCl) was successfully carried out and characterized using various techniques. Furthermore, the optimization of hydrogel was done by varying the amount of carboxyl methyl tamarind kernel gum (CMTKG), N, N′-methylene-bis-acrylamide (MBA) or potassium persulphate (KPS), and their influence on the swelling ratio was examined. The fabricated hydrogels were characterized by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM), whereas thermal stability was confirmed by thermogravimetry analysis (TGA). The hydrogels’ swelling ratio and in vitro drug release studies were assessed in pH 1.2 and 7.4 buffer solutions and showed better results in alkaline pH. The drug release profile of metformin-loaded CMTKG/PSA/XG hydrogel obeyed the Korsmeyer–Peppas model and follow non-Fickian diffusion in pH 7.4 and Fickian diffusion mechanism at pH 1.2. This pH-dependent behaviour of the metformin HCl-loaded CMTKG/PSA/XG hydrogel could be applicable for site-specific release of metformin HCl.