Disclosed is a pharmaceutical composition for oral administration, comprising 1-{5-[(5-{[(2R)-2-ethylpyrrolidin-1-yl]methyl}-4-[4-methoxy-3-(trifluoromethyl)phenyl]-1,3-thiazol-2-yl)carbamoyl]pyrazin-2-yl}pyperidine-4-carboxylic acid, which is a compound having pH-dependent solubility, or a pharmaceutically acceptable salt thereof, and a cellulose derivative. In the pharmaceutical composition for oral administration, the solubility and absorbability of the drug are improved.