The present invention relates to a stable pharmaceutical composition comprising a compound represented by formula (I), its pharmaceutically acceptable salt or a solvate thereof. The stable pharmaceutical composition can be prepared by comprising 1) a compound represented by formula (I), its pharmaceutically acceptable salt, or a solvate thereof, 2) one or more selected from the group consisting of alkali metal chlorides, alkaline earth metal chlorides, transition metal chlorides and magnesium chloride; and 3) sugar and/or a sugar alcohol.