Disclosed is a technique for improving the water solubility and storage stability of 7-(3S,4S)-3-[(cyclopropylamino)methyl]-4-fluoropyrrolidine-1-y1}-6-fluoro-1-(2-fluoroethyl)-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (compound (1)) that is safe and not only has a strong antibacterial action but also is effective for resistant bacteria for which conventional antibacterial agent are less effective. Crystals of the hydrochloride salt of the compound (1), crystals of the hydrochloride salt hydrate of the compound (1), and crystals of the methanesulfonate salt of the compound (1) are provided. In these crystals, decomposition due to influences of light is suppressed as compared to that in crystals of the compound (1) in free, and their storage stability is high. These crystals have higher solubility in water than the crystals of the compound (1) in free.
本技术公开了一种安全的提高7-(3S,4S)-3-[(环丙基
氨基)甲基]-4-
氟吡咯烷-1-yl}-6-
氟-1-(2-
氟乙基)-8-甲氧基-
4-氧代-1,4-二氢喹啉-3-羧酸(化合物(1))的
水溶性和储存稳定性的技术。该化合物不仅具有强大的抗菌作用,而且对传统抗菌剂无法有效对抗的耐药菌也具有有效作用。本技术提供了化合物(1)的盐酸盐晶体、化合物(1)的盐酸盐
水合物晶体和化合物(1)的
甲磺酸盐晶体。这些晶体相比于自由状态的化合物(1)的晶体,能够抑制光的影响导致的分解,储存稳定性高。这些晶体在
水中的溶解度比自由状态的化合物(1)的晶体更高。