Abstract: A pharmaceutical composition is provided herein containing as a key ingredient 4-carbamoyl-imidazolium-5-oleate of the formula (I) ##STR1## its salt or hydrate thereof, and one or more of a sulfur compound capable of producing at least one of the ions selected from HSO.sub.3.sup.--, SO.sub.3.sup.2-- and S.sub.2 O.sub.5.sup.2--. The sulfur compounds prevent discoloration of the composition.The stabilization against coloration is further enhanced by the presence of L-cysteine hydrochloride. The solubility of the compound (I) can be further enhanced by the presence of a basic substance. The active ingredient is known as a therapeutic agent for the treatment of such diseases as rheumatism and nephritis.