Development and characterization of mucoadhesive-thermoresponsive gels for the treatment of oral mucosa diseases

Introduction: The mucositis is an inflammatory, erosive and ulcerative process of the oral mucosa. It is usually caused by radiation, chemotherapy, infections, diabetes, smoking and it is characterized by severe pain and difficulty eating and can have a very serious impact on quality of life. A suitable treatment must ensure pain control and mechanical protection to promote mucosal healing. The purpose of this work was to study an in-situ gelling formulation to be sprayed onto the damaged oral mucosa by self-administration. The formulation must be able to quickly form a film when applied in the oral cavity. Methods: many batches were prepared mixing a thermosensitive polymer (poloxamer PF127 or P123) with mucoadhesive polymers polyvinylpyrrolidone (PVP), sodium carboxymethyl cellulose (NaCMC), Carbopol 971P, chitosan (CS). By an experimental design three suitable formulations were identified and loaded with the model drug benzydamine hydrochloride. The hydrogel based on 25.50% PF127, 0.20% PVP and 0.35% CS maintained its original properties (gelling, rheological and mucoadhesive) after loading and showing a sustained drug release. Conclusions: the selected hydrogel showed to be suitable for the treatment of mucositis, able to reduce the number of daily administration and to protect the damaged mucosa from mechanical and chemical solicitations.