ABSTRACT:
Chitosan based polyelectrolyte complexes (PEC) were developed in the form of beads and hydrogels using simple ionic gelation technique by interaction of positively charged chitosan with negatively charged sodium alginate, carboxymethyl cellulose sodium and -carrageenan. The surface morphology was investigated by scanning electron microscopy, which showed that spherical or disc shaped beads were formed by changing counter-ion and the hydrogels showed smooth and rough surfaces. The polyelectrolyte complex formation was confirmed by DSC and FTIR. The beads were evaluated for drug entrapment, particle size and the matrix tablets were evaluated for tablet parameters. The mean particle size of beads was 544.89 to 891.15 ?m. The entrapment of metoprolol tartrate in beads was 43.43 to 57.42%. The increase in the concentration of chitosan increased the mean particle size and drug entrapment. The Metoprolol tartrate extended release matrix tablets were prepared by direct compression of polyelectrolyte complex hydrogels. Hydrogel beads and extended release tablets were evaluated for swelling behavior and in vitro release. The hydrogel beads and matrix tablets showed pH sensitive swelling with low swelling in HCl buffer, while more swelling in phosphate buffer. The in vitro release of metoprolol tartrate was very slow in HCl buffer and was rapid in phosphate buffer. The in vitro release of metoprolol tartrate was in the order of chitosan-carboxymethylcellulose sodium < chitosan-sodium alginate< chitosan- -carrageenan. Hence chitosan based polyelectrolyte complex containing carboxymethylcellulose sodium was found to extended the release of metoprolol tartrate up to 12 h.