Chitosan ascorbate: a chitosan salt with improved penetration enhancement properties.

The aim of the present work was to investigate if chitosan salification with ascorbic acid could produce an increase in chitosan penetration enhancement properties towards buccal mucosa and intestinal Caco-2 cell monolayer. Three different chitosan grades were considered. Chitosan hydrochloride and lactate were used as references. Fluorescein isothiocyanate-dextran (FD4), a hydrophilic high MW molecule, was employed as model penetrant. Chitosan ascorbate showed better penetration enhancement properties towards both buccal porcine mucosa and Caco-2 cell monolayer with respect to hydrochloride and lactate salts. Cytotoxicity of chitosan ascorbate assessed on Caco-2 cells was comparable with those of chitosan hydrochloride and lactate.