PROBLEM TO BE SOLVED: To provide pharmaceutical compositions containing ferric citrate in the form exhibiting high aqueous solubility, effective in treating or alleviating chronic kidney disease.SOLUTION: A pharmaceutical composition contains ferric citrate 70 in a form having a dissolution rate of at least 2 mg/cm2/min, or 2 to 4 mg/cm2/min. A method comprises administering the composition in a dosage form suitable for oral administration such as a tablet, at a dose of 2 to 20 mg/day of the ferric citrate 70.SELECTED DRAWING: Figure 1【課題】慢性腎疾患の治療又は緩和に有効な、高い水溶性を示す形態のクエン酸第二鉄を含む医薬組成物の提供。【解決手段】溶解速度が少なくとも2mg/cm2/分、又は2～4mg/cm2/分である形態のクエン酸第二鉄70を含む医薬組成物。クエン酸第二鉄７０を２～２０ｍｇ／日の用量で、組成物を、錠剤等の経口投与に適した剤形で投与する方法。【選択図】図１
