Fluid bed granulation as an innovative process to produce dry redispersible nanocapsules: Influence of cationic coating of particles

Abstract The application of nanocarrier aqueous suspensions as drug delivery systems offers an important challenge for formulators: their reduced physicochemical stability during storage. Here, a novel approach to produce dry redispersible nanocapsules by fluid bed granulation intended for oral administration is proposed. In addition, the influence of the cationic coating of nanoparticles on the properties of granules was evaluated. Lipid-core nanocapsules were prepared in aqueous dispersion with or without a cationic coating by chitosan to be used as the granulating liquid in the fluid bed granulation process. Granule properties, like volume-based mean particle size, yield, moisture content, morphological characteristics, flow properties, and redispersion behavior were evaluated. The granulation process had a yield close to 90%, affording granules with moisture content lower than 4% and good flow properties. Nanocapsules adhered to the surface of the primary particles which agglomerating to form the granules, but were released upon redispersion in water. Moreover, cationic coating of the nanocapsules improved the aqueous redispersion behavior of granules. In conclusion, this novel approach to produce granules as an intermediate or final dosage form by fluid bed granulation represents an innovative process to develop new oral nanomedicines. Furthermore, the cationic coating of nanocapsules has an important role on the aqueous redispersion properties of these granules.