Chitosan-based hydrogels for nasal drug delivery: from inserts to nanoparticles.

IMPORTANCE OF THE FIELD: Chitosan represents a multifunctional polymer, featuring both mucoadhesive and permeation-enhancing properties and therefore is a widely studied excipient for mucosal drug delivery. As regards nasal administration, chitosans have been used for the preparation of gels, solid inserts, powders and nanoparticles in which a three-dimensional network can be recognized. AREAS COVERED IN THIS REVIEW: This review provides a discussion of the different nasal dosage forms based on chitosan hydrogels. In the first section intranasal delivery is discuss as a useful tool for non-invasive administration of drugs intended for local or systemic treatments. Then chitosan-based hydrogels are described with a focus on their mucoadhesive and permeation-enhancing ability as well as their capacity of controlled drug release. Finally, a detailed discussion regarding several examples of the different nasal dosage forms is reported, including considerations on in vitro, ex vivo and in vivo studies. WHAT THE READER WILL GAIN: Summary and discussion of recent data on the different pharmaceutical forms based on chitosan hydrogels could be of interest to researchers dealing with nasal drug delivery. TAKE HOME MESSAGE: The aim of this review is to stimulate further investigations in order to achieve the collection of harmonized data and concrete clinical perspectives.