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}piperidine-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 medicinal substance are improved.本發明揭示一種溶解性具有pH相依性，含有1-{5-[(5-{[(2R)-2-乙基吡咯嗪-1-基]甲基}-4-[4-甲氧基-3-(三氟甲基)苯基]-1,3-噻唑-2-基)胺甲醯基]吡嗪-2-基}哌啶-4-羧酸或其在製藥學上被容許的鹽類、及纖維素衍生物之經口投與用醫藥組成物。前述經口投與用醫藥組成物中，前述藥物之溶解性及吸收性獲得改善。
