An internal liquid agent containing ambroxol hydrochloride, a pigment, polyethylene glycol, and optional gallic acid or a derivative thereof,is an internal liquid agent, in which changes in color of the ambroxol hydhrochloride caused by irradiation of light are inhibited, no precipitate is formed, discoloration of the pigment caused by heat is inhibited, and bitter taste of ambroxol hydrochloride is suppressed.