Disclosed is a controlled release nucleated tabletwhich is composed of an inner nucleus and an outer layerthat covers the inner nucleus and is capable of maintainingthe level of 2-(3-cyano-4-isobutyloxyphenyl)-4-methyl-5-thiazolecarboxylicacid in the blood to a certain value orhigher for a long period of time. The controlled releasenucleated tablet is characterized in that the inner nucleuscontains 2-(3-cyano-4-isobutyloxyphenyl)-4-methyl-5-thiazolecarboxylic acid and the outer layer contains2-(3-cyano- 4-isobutyloxyphenyl)-4-methyl-5-thiazolecarboxylicacid and a gel-forming water-soluble polymer that is in anamount of 16 (w/w)% or more relative to the weight of theouter layer.
