Formulation of sustained release matrix tablet using Chitosan/Ghatti gum polyelectrolyte complex

Chitosan/ghatti gum polyelectrolyte complexes were synthesized using different proportions of chitosan (CH) and ghatti gum (GG). The optimum CH: GG ratio was 20:80, which produced highest product yield. Polyelectrolyte (PEC) samples were characterized by differential scanning calorimetry (DSC) and FT-IR spectroscopy. Matrix tablets using PEC as matrix and Diltiazem Hcl as a model drug were formulated by wet granulation technique. The matrix tablets were evaluated for pharmacotechnical properties, in vitro release and release data analysis. FT-IR studies confirmed that PEC formed a complex through an electrostatic interaction between the NH3 + groups of CH and the carboxylate (COO-) group of ghatti gum. In vitro drug release results showed that, the optimum formulation showed controlled release for more than 12hrs. The drug release from this tablet showed a pH-independent release profile and the release profile of Diltiazem Hcl from the respective tablets followed first order kinetics and the mechanism follows non-fickian (anamolous) transport. The results of the present study indicated that polyelectrolyte complex of CH and GG can be used as an effective matrix former to extend the release of the Diltiazem Hcl.