The purpose of the present invention is to provide a pharmaceutical composition that contains a specific compound and exhibits a superior preservation efficacy, the specific compound being stable within the pharmaceutical composition, and to provide methods for improving the stability of the specific compound within the pharmaceutical composition and the preservation efficacy of the pharmaceutical composition. The pharmaceutical composition according to the present invention contains (6-{[4-(pyrazol-1-yl)benzyl](pyridin-3-ylsulfonyl)aminomethyl}pyridin-2-yl amino) isopropyl acetate or a salt thereof, and further contains edetic acid or a salt thereof.
