Development, characterization, and in vitro assessment of multilayer mucoadhesive system containing dexamethasone sodium phosphate

The main goal of this work is the design of a mucoadhesive system, based on three layers for the unidirectional release of dexamethasone sodium phosphate (DEX-F) for possible use in the oral mucosal cavity. The different layers were created by the electrospinning process, using polyvinylpyrrolidone (PVP) and poly(epsilon-caprolactone) (PCL)as polymeric base and polycarbophil (NOVEON (R) AA-1, PCF) as adhesion enhancer. The system contains a drug-release layer, an adhesive layer and a backing layer. The nanofibers matrices were characterized morphologically by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC); in vitro drug content, degradation time and ex vivo mucoadhesive properties studies were performed. SEM images showed the formation of fibers with a variable diameter and porosity between the layers. Thermal studies TGA and DSC indicated an excellent thermal stability for materials. In vitro studies show a drug content release of 79.86%+/- 13.5% of the loaded drug in a 4 h release period. Mucoadhesive evaluation exhibit excellent characteristics for a mucosal adhesion. The produced electrospun mucoadhesive patch exhibited an excellent stability, thermal properties, mucoadhesive properties, and the appropriate amount of drug released, promising features for successful DEX-F delivery in a mucoadhesive system for oromucosal surface.