CRYSTAL OF 7-{(3S,4S)-3-[(CYCLOPROPYLAMINO)METHYL]-4-FLUOROPYRROLIDIN-1-YL}-6-FLUORO-1-(2-FLUOROETHYL)-8-METHOXY-4-OXO-1,4-DIHYDROQUINOLINE-3-CARBOXYLIC ACID
PROBLEM TO BE SOLVED: To provide a technique for improving solubility in water and storage stability of 7-{(3S,4S)-3-[(cyclopropylamino)methyl]-4-fluoropyrrolidin-1-yl}-6-fluoro-1-(2-fluoroethyl)-8-methoxy-4-oxo-1,4- dihydroquinoline-3-carboxylic acid (compound (1)) which not only shows safe and powerful antibacterial activity but also is effective against resistant bacteria against which conventional antibacterial agents scarcely show effectiveness.SOLUTION: Hydrochloric acid salt crystals, hydrochloric acid salt hydrate crystals, and a methane sulfonic acid salt crystals of a compound (1) are provided. These crystals are more suppressed from decomposition due to an effect of light and have higher storage stability when compared with crystals of the free form compound (1). Further, these crystals have higher water solubility when compared with crystals of the free form compound (1).SELECTED DRAWING: None【課題】 安全で、強力な抗菌作用を示すだけではなく、従来の抗菌剤が効力を示しにくい耐性菌に対して有効である７－｛（３S、４S）－３－［（シクロプロピルアミノ)メチル］－４－フルオロピロリジン－1－イル｝－６－フルオロ－１－（２－フルオロエチル）－８－メトキシ－４－オキソ－１、４－ジヒドロキノリン－３－カルボン酸（化合物（１））の水に対する溶解性、かつ、保存安定性を改善する技術を提供する。【解決手段】化合物（１）の塩酸塩結晶、塩酸塩水和物結晶、およびメタンスルホン酸塩結晶を提供する。これら結晶は、遊離型の化合物（１）の結晶に比べ、光の影響による分解が抑制されており、保存安定性が高い。また、これら結晶は、遊離型の化合物（１）の結晶に比べ、水への溶解性も高い。【選択図】 なし
