INTERPOLYMER COMPLEXATION AND ITS EFFECT ON BIOADHESIVE STRENGTH AND DISSOLUTION CHARACTERISTICS OF BUCCAL DELIVERY SYSTEMS

During the process of development of mucoadhesive buccal delivery syst ems, interpolymer complex formation between carboxy vinyl polymer, whi ch is similar to polyacrylic acid and other polymers as hydroxypropyl cellulose, carbopol-934, sodium carboxymethyl cellulose and. polyvinyl pyrrolidone was studied as a function of pH. It was observed-that car bopol-934 shows strong complexation with polyvinyl pyrrolidone and hyd roxypropyl cellulose, but very little with sodium carboxymethyl cellul ose. The degree of complexation is higher at acidic pH and decreases w ith an increase in pH. In further studies, when mucoadhesive buccal ta blets were prepared using these polymer combinations, it was observed that the degree of complexation between the two polymers affected the rate and extent of drug release and also the bioadhesive strength of t he tablets.