DRUG-RELEASE FROM ORAL MUCOSAL ADHESIVE TABLETS OF CHITOSAN AND SODIUM ALGINATE

Oral mucosal bioadhesive tablets of diltiazem were prepared by directly compressing the drug with a mixture of chitosan and sodium alginate. In vitro adhesion studies indicated adhesion properties comparable to those of a commercial formulation. In vitro release of diltiazem was rapid and could be modified by changing the mixing ratio of chitosan and sodium alginate; increasing the chitosan content in the tablets and/or the viscosity grade of the alginate resulted in a decrease in the in vitro release rate. The bioavailability of diltiazem was 69.6% from tablets with a 1:4 chitosan/alginate weight ratio when administered sublingually to rabbits compared with 30.4% by oral administration.