An oral bioadherent gel containing polyvinylpyrrolidone (PVP) and sodium hyaluronate with muco-protective activity. Upon oral application, this gel adheres to the mucosal surface of the mouth and throat, forming a thin layer that acts as a barrier to protect exposed and sensitized nerve endings from the painful stimuli associated with eating, drinking, and talking. orA gel used to lessen pain from mouth sores caused by chemotherapy or radiation therapy, oral surgery, braces, or disease. Polyvinylpyrrolidone-sodium hyaluronate gel is being studied in the treatment of pain caused by mouth sores in children receiving cancer treatment. It forms a thin layer over the surface of the mouth and throat to prevent irritation while eating, drinking, and talking. Also called Gelclair.