Development of Buccal adhesive formulations using in-situ formation of interpolymer complex and optimization using Box-Benhken design

Extended release bioadhesive buccal tablets for delivery of Nisoldipine were developed using in-situ formation of interpolymer complex providing significantly different attributes to that of individual polymers. When tablet made up of Gantrez and Povidone comes in contact with aqueous solution, complexation through the hydrogen bond formation takes place which was characterized by Infrared spectroscopy. Interpolymer complex resulted to reduced solubility of polymer. A Box-Behnken factorial design was selected to explore effects on bioadhesive strength and drug release by interaction of Gantrez and Povidone. Such effects were confirmed by significant regression coefficient having p less than 0.05. Three check points were also taken into account to validate the polynomial equation. Results show that polymers change the drug release mechanism which is confirmed by model fitting into dissolution point. By optimizing the ratio of polymers to achieve desired release (90%) in the sixth hour and good BAS were obtained for batch G17. Keywords: Bioadhesive, Nisoldipine, Gantrez, Polyvinyl povidone, Box-Behnken design, Polynomial equation.