Pectin-based bioadhesive delivery of carbenoxolone sodium for aphthous ulcers in oral cavity

The objective of this study was to prepare and evaluate the pectin-based dosage form for buccal adhesion. Carbenoxolone sodium, which is used for the treatment of aphthous ulcers in oral cavity, was used as a model drug. The pectin buccal discs were prepared by direct compression. The water uptake and erosion of pectin disc increased progressively with the swelling time. The bioadhesion of dried pectin discs decreased when either the discs were hydrated or the buccal tissue was wet with a small volume of medium. The influencing factors such as pectin type, pectin to lactose ratio, and sweetener type on the formulations were investigated. The results demonstrated that buccal discs prepared from pectin with a high degree of esterification (DE) showed a weaker and more friable characteristic than that with low DE. Decreasing pectin to lactose ratio resulted in the high dissolution rate with low bioadhesive properties. Addition of sweetener in the formulations also affected the hardness, friability, and bioadhesive properties of the discs. The pectin discs containing sweetening agent showed a higher drug release than those without sweetener. The results suggested that pectin-based bioadhesive discs could be used to deliver carbenoxolone sodium in oral cavity.