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.