Disclosed is a controlled release nucleated tablet which is composed of an inner nucleus and an outer layer that covers the inner nucleus and is capable of maintaining the level of 2-(3-cyano-4-isobutyloxyphenyl)-4-methyl-5- thiazolecarboxylic acid in the blood to a certain value or higher for a long period of time. The controlled release nucleated tablet is characterized in that the inner nucleus contains 2-(3-cyano-4-isobutyloxyphenyl)-4-methyl-5- thiazolecarboxylic acid and the outer layer contains 2-(3-cyano- 4-isobutyloxyphenyl)-4-methyl-5-thiazolecarboxylic acid and a gel-forming water-soluble polymer that is in an amount of 16 (w/w)% or more relative to the weight of the outer layer.本發明係關於一種釋出控制性錠劑，係為可使2-(3-氰基-4-異丁氧基苯基)-4-甲基-5-噻唑羧酸之藥物血中濃度長時間維持在一定值以上，且由內核與被覆該內核之外層部所構成之錠劑，該內核中含有2-(3-氰基-4-異丁氧基苯基)-4-甲基-5-噻唑羧酸，該外層部中含有相對於2-(3-氰基-4-異丁氧基苯基)-4-甲基-5-噻唑羧酸外層部之重量為16(w/w)%以上之凝膠形成性水溶性高分子。
