Hyaluronic acid, also known as hyaluronate, is a carbohydrate substance that is present in connective, epithelial, and neural tissues and is a major component of the intracellular matrix. Sodium hyaluronate is the sodium salt of the same substance. Hyaluronic acid or sodium hyaluronate has been used in patients with cancer as an oral spray for treatment of mucositis and as a topical treatment for radiodermatitis.