Preparation and Characterization of Calcium Cross-linked Carboxymethyl Tamarind Kernel Polysaccharide as Release Retardant Polymer in Matrix

Abstract

This study aims to improve the efficacy of carboxymethyl tamarind kernel polysaccharide by cross-linking with Ca2+ ion and preparing its diclofenac sodium loaded matrix tablets for sustained drug delivery applications. Ionic gelation technique was used for cross-linking, and calcium chloride was used as a cross-linking agent. The native and cross-linked polysaccharide was characterized to analyze the change. The successful cross-linking of calcium was confirmed by infrared spectra by evaluating change in the functional group, while diffraction patterns revealed the change in crystallinity behavior. The thermal property of modified gum was also improved after Ca2+ cross-linking, whereas microscopical images of both gums revealed the gum's change in shape and surface. Further, calcium cross-linked carboxymethyl tamarind kernel polysaccharide was formulated into a matrix tablet using diclofenac sodium. The weight variation, thickness, hardness, friability, content uniformity, moisture content, swelling index, and in vitro release kinetics were also evaluated. The in vitro release study revealed that modified gum tablets showed a sustained release of diclofenac sodium providing a release of 50.84 % of drug over 24 hours, following first-order kinetics with a super case – II transport mechanism. So, the results indicate that calcium cross-linking of CMTKP modifies its release behavior, making it suitable for preparing sustained release pharmaceutical formulation.