[Problem] Provided is a pharmaceutical composition which suppresses gelation of the 7-{(3S,4S)-3-[(cycloproropylamino)methyl]-4-fluoropyrrolidine-1-yl}-6-fluoro-1-(2-fluoroethyl)-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid hydrochloride and which suppresses elution delay.[Solution] This solid pharmaceutical composition is obtained by using crystals (B-form crystals) of a hydrate of 7-{(3S,4S)-3-[(cyclopropylamino)methyl]-4-fluoropyrrolidine-1-yl}-6-fluoro-1-(2-fluoroethyl)-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid hydrochloride, having peaks at 9.4 and 17.7 degrees (±0.2 degrees for each angle) as 2θ diffraction angles in X-ray powder diffraction using CuKα emission.
