Thermally sensitive gels based on chitosan derivatives for the treatment of oral mucositis

The aim of the present work was the development of a thermally sensitive mucoadhesive gel based on chitosan derivatives for the treatment of oral mucositis. Trimethyl chitosan (TMC) and methylpyrrolidinone chitosan (MPC) were considered. They were mixed with glycerophosphate (GP) according to different polymer/GP molar ratios and characterized for gelation properties by means of rheological analysis in comparison with chitosan. The influence of molecular weight and substitution degree (SD) of TMC on gelation temperature and time was investigated. The mucoadhesive properties of the mixtures were also assessed using porcine buccal mucosa. The best properties were shown by TMC with high MW and low SD mixed with GP according to 1:2 molar ratio. Such mixture was loaded with benzydamine hydrochloride, an anti-inflammatory drug with antimicrobial properties and subjected to in vitro drug release and wash away test. The formulation based on TMC/GP mixture was able to prolong drug release and to withstand the removal physiological mechanisms. The antimicrobial properties of both vehicle and formulation were investigated. Also in absence of drug, TMC/GP mixture was characterized by antimicrobial properties.