PROBLEM TO BE SOLVED: To provide a novel therapeutic agent for hyperproliferative disease, autoimmune disease, and heart disease.SOLUTION: The invention relates to a liquid composition which is an aqueous solution of 3-quinuclidinone derivatives represented by formula I, wherein the aqueous solution has a pH from about 3.0 to about 5.0 which is adjusted with a pH adjuster. The liquid composition can be used for the treatment of diseases selected from hyperproliferative disease, autoimmune disease, and heart disease.SELECTED DRAWING: Figure 1【課題】過剰増殖性疾患、自己免疫疾患および心疾患の新規治療薬の提供。【解決手段】式Iで表される3-キヌクリジノン誘導体の水溶液である液体組成物であって、前記水溶液がpH調整剤により約3.0~約5.0のpHを有する、組成物。前記液体組成物を、過剰増殖性疾患、自己免疫疾患および心疾患から選択される疾患の治療に使用することができる。【選択図】図1