Preparation and characterization of chitosan succinate as coating polymer for enteric-coated tablet

Objective: This present study was aimed to evaluate the potential of chitosan succinate as a coating polymer. Methods: In this study, chemical modification of chitosan was performed by substituting a succinate group into chitosan’s amine group. This reaction used a water-solvent method to obtain chitosan succinate. Chitosan succinate was characterized and used as a coating agent in enteric-coated tablet dosage forms containing sodium diclofenac as the drug model at concentrations of 3% and 4% and combined it with hydroxypropyl methylcellulose phthalate (HPMCP) in ratios of 3:1 and 2:1 (3%). The obtained tablets were evaluated based on their physical appearance, uniformity of weight and size, thickness film, disintegration time for an hour in acid, and dissolution profile. Results: Although the enteric-coated tablets with 3% and 4% chitosan succinate dissolved after 1 h in acid, they could not hold drug release in the acid medium under 10%. The enteric-coated tablet combined with chitosan succinate and HPMCP (3:1 and 2:1) at 3% did not dissolve after 1 h in the acid medium and could hold drug release up to 8.53% in acid. Conclusion: A combination of chitosan succinate and HPMCP (3:1 and 2:1) at 3% has a better ability to hold drug release in acid medium and met the requirement as a coating in enteric-coated tablet dosage forms.