pH sensitive alginate-chitosan hydrogel beads for carvedilol delivery.

Alginate-chitosan hydrogel beads for carvedilol delivery were prepared to be used as a controlled pH-sensitive drug delivery system. The beads were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. The swelling ability and in vitro release of carvedilol in solutions of different pH value were investigated. They exhibited significant swelling rates when exposed to the slightly alkaline environment. The results suggest that the system has potential to be used as an effective pH-controlled delivery system for carvedilol. The release of carvedilol at various pH values was analyzed by a semi-empirical equation.