Controlled fluoride release for osteoporosis treatment using orally administered chitosan hydrogels

Abstract Chitosan - β-glycerophosphate hydrogels have been widely studied for biomedical applications in recent years. In the current study a Chitosan - β-glycerophosphate hydrogel was evaluated as a platform for sodium fluoride release in the gastrointestinal tract. For this purpose, microscopy observation, infrared spectroscopy, stability, rheology studies and in vitro release assays were carried out. The hydrogel was stable for at least 48 h when exposed to an aqueous media in a pH range from 4 to 7 and the release of sodium fluoride was controlled for more than 6 h. In vivo studies were carried out in order to evaluate the oral administration of sodium fluoride using the hydrogel in comparison to a water solution. Fluoride pharmacokinetic was similar when the drug was administered with both formulations. Nevertheless, fluoride absorption was greater when the drug was given with the hydrogel, and further, drug-related side effects were absents. These results suggest that Chitosan - β-glycerophosphate hydrogel could be a good candidate for sustained release of fluoride in oral formulation.