Disclosed is a pharmaceutical composition comprising rebamipide (2-(4-chlorobenzoylamino)-3-[2(IH)-quinolon-4-yl] propionic acid) having a concentration between 10-50 mg/ml rebamipide, a mean particle size of less than 500 nm, a dispersing agent, and a viscosity enhancing agent, wherein the dispersing agent is selected from polyvinylpyrrolidone, hydroxypropylmethylcellulose, polyoxyethylene polyoxy-propylene glycol, or carboxymethylcellulose sodium and the viscosity agent is selected from polyvinylpyrrolidone or pullulan. Also disclosed is the use of the pharmaceutical composition as a gargle or a liquid preparation for swish and swallow for preventing and/or treating stomatitis caused by radiotherapy.
