Disclosed is a pharmaceutical composition comprising (E)-3,5-dihydroxy-7-[4'-4"-fluorophenyl-2'-cyclopropyl-quinolin-3'-yl]-6-heptenoic acid, or its salt or ester, of which the aqueous solution or dispersion has a pH of from 7 to 8. The composition has good time-dependent stability and has no change in its outward appearance even after having been stored long.