Development and assessment of carboxymethyl tamarind kernel gum-based pH-responsive hydrogel for release of diclofenac sodium

Abstract

The current research work focuses on the fabrication of carboxymethyl tamarind kernel gum/polyvinylpyrrolidone/polyacrylamide (CMTKG/PVP/PAM) based hydrogel and its loading was done with diclofenac sodium drug (DS) to obtain smart pH-responsive hydrogels. In addition, the effect of concentration of cross-linker- N, N′-methylene bis(acrylamide) (MBA), biopolymer (CMTKG), as well as initiator- potassium persulphate (KPS) on the swelling behavior of smart hydrogel was also analyzed. The synthesized hydrogels were characterized using Scanning Electron Microscopy (SEM), Powder X-ray Diffraction (PXRD), Thermogravimetry Analysis (TGA), and Attenuated Total Reflection-Fourier Transform Infrared spectroscopy (ATR-FTIR). ATR-FTIR confirms the successful formation of hydrogels, while PXRD and SEM indicate the amorphous and porous nature of the polymeric network. The TGA results indicate higher thermal stability for DS-loaded hydrogel than unloaded hydrogel. However, sol–gel analysis shows a rise in gel fraction, with increased concentrations of CMTKG, MBA, and KPS. The swelling ratio as well as the release of DS were found to be higher under slightly alkaline conditions. The result of drug loading and release indicates that PVP increases drug loading (%) and release (%). The drug release behavior of DS-loaded hydrogel follows the Fickian mechanism of diffusion with the Korsmeyer-Peppas model as the best-fitted one. The synthesized DS-loaded CMTKG/PVP/PAM hydrogels could be a promising substitute for prolonged delivery of sparingly soluble DS in pH 7.4.