PROBLEM TO BE SOLVED: To provide (1) an aqueous liquid preparation containing an azulene derivative and excellent in the stability of the azulene derivative, (2) a method for improving the stability of the azulene derivative, or (3) a stability-improving agent for the azulene derivative.SOLUTION: This aqueous liquid preparation is obtained by using the azulene derivative and tocopherol acetate ester in combination, and contains at least one selected from the group consisting of dibutylhydroxytoluene (BHT) and cationic surfactants.COPYRIGHT: (C)2011,JPO&INPIT【課題】(1)アズレン誘導体を含有する水性液剤であって、アズレン誘導体の安定性に優れる水性液剤、(2)アズレン誘導体の安定性を向上する方法、又は(3)アズレン誘導体に対する安定性向上剤を提供する。【解決手段】アズレン誘導体とトコフェロール酢酸エステルを併用する。【選択図】なし
