Synthesis of gum kondagogu-g-poly(N-vinyl-2-pyrrolidone) and its evaluation as a mucoadhesive polymer

The purpose of the present study was to synthesize gum kondagogu-g-poly(N-vinyl-2-pyrrolidone) and to evaluate its mucoadhesive properties. UV-assisted graft co-polymerization of N-vinyl-2-pyrrolidone on gum kondagogu was carried out employing three-factor, three-level central composite experimental designs. It was observed that the concentrations of N-vinyl pyrrolidone and ammonium persulphate exerted a significant antagonistic and synergistic influence on grafting efficiency respectively. The graft co-polymer was characterized by FT-IR, DSC and SEM study. Mucoadhesive properties of the graft-copolymer were evaluated by formulating buccal discs employing metronidazole as the model drug. On comparative evaluation buccal discs formulated using gum kondagogu-g-poly(N-vinyl pyrrolidone) showed higher ex vivo bioadhesion time than the discs formulated using gum kondagogu. In vitro release study showed an almost similar release profile of metronidazole from the buccal discs of gum kondagogu and gum kondagogu-g-poly(N-vinyl-2-pyrrolidone). Thus, grafting of N-vinyl-2-pyrrolidone on gum kondagogu enhances its mucoadhesion without significantly affecting the release behaviour.