Patent attributes
This invention is aimed to provide a stabilized formulation of ramosetron or a pharmaceutically acceptable salt thereof under a temperature/humidity condition, especially at a low content and relates to a stable oral solid drug composition of ramosetron or a pharmaceutically acceptable salt thereof, which is characterized by containing one or two or more members selected from the group consisting of an aliphatic carboxylic acid or an ester thereof, a hydroxycarboxylic acid or an ester thereof, an acidic amino acid, an enolic acid, an aromatic carboxyl compound or an ester thereof, and a carboxyl group-containing high-molecular substance, and to a stabilization method of the same. Also, this invention relates to a therapeutic agent of diarrhea-predominant irritable bowel syndrome containing from 0.002 to 0.02 mg of ramosetron hydrochloride as a daily dose or an equivalent molar amount of ramosetron or its pharmaceutically acceptable other salt as an active ingredient.