Spray-dried carvedilol-loaded nanocapsules for sublingual administration: Mucoadhesive properties and drug permeability

The aim of this study was to produce redispersible spray-dried carvedilol-loaded nanocapsules and to evaluate their mucoadhesiveness as well as drug permeability performance the across sublingual mucosa in the presence or absence of simulated salivary flux. Furthermore, the effects of saliva as redispersion medium on drug release and drug permeability were invetigated. Carvedilol-loaded nanocapsules were produced with Eudragit® RS 100 [EUD] or poly(ε-caprolactone) [PCL] as polymer shell. Powders were produced by spray drying using a mixture of lactose/polyvinylpyrrolidone as drying adjuvant. The recovery of the original nanoparticles after the redispersion of powders was analyzed considering their size, morphology, and mucoadhesive properties, which were not altered by the drying process. The powders interacted with the sublingual porcine sublingual, and this interaction was measured through the technique of texture analysis. Redispersed nanocapsules controlled drug release, and drug diffusion flux was slower from PCL-nanocapsules than EUD-nanocapsules. This control was greater when artificial saliva was used as redispersion medium for PCL-nanocapsules. Carvedilol permeated across porcine sublingual mucosa at the same likewise as it was released. The presence of artificial saliva influenced drug solubility, and the drug permeability profiles of nanocapsules were similar, regardless of the polymer shell. Redispersed nanocapsules improved the concentration of carvedilol retained on the sublingual mucosa and increased the amount of permeated drug in the presence of simulated salivary flux. This study highlighted the suitability of using spray-dried powders containing nanocapsules as a platform for the development of innovative sublingual solid dosage forms for carvedilol administration.