Development of smart alginate/chitosan grafted microcapsules for colon site-specific drug delivery

IN THIS study, a smart delivery system for colon site-specific release of diclofenac sodium (DS) was developed based on alginate grafted chitosan (Alg-g-CS) microcapsules. The developed microcapsules were characterized using FTIR and SEM characterization tools, while the present amine content on the alginate microcapsules surface was estimated by ion exchange capacity (IEC) measurements. Besides, both swelling and in vitro drug release profiles were studied at colon pH medium (pH7.4). The results showed an increase in IEC values from 1.1 to 3.6meq/g with increasing CS concentration from 0.1 to 0.5%. Moreover, grafting of alginate microcapsules with chitosan prevented the drug burst release as well as protected alginate microcapsules from the fast disintegration at colon conditions. The gained results clearly suggested that the developed smart Alg-g-CS (0.5%CS) microcapsules could be used effectively for the delivery of diclofenac sodium (DS) to colon tract.