Formulation having improved ph-dependent drug- release characteristics, containing esomeprazole or pharmaceutically acceptable salt thereof

A pharmaceutical formulation comprising:

• (a) a core containing esomeprazole or a pharmaceutically acceptable salt thereof as an active ingredient;
• (b) an endothelial coated layer formed on the core;
• and
• (c) a release-control coated layer formed on the endothelial coated layer,
• wherein the endothelial coated layer comprises at least one selected from the group consisting of hydroxypropyl methyl cellulose (HPMC), polyvinyl pyrrolidone (PVP), low-substituted hydroxypropyl cellulose (HPC-L), starch, gelatin and ethyl cellulose (EC),
• the release-control coated layer comprises a polymer in which a methacrylic acid copolymer S and a methacrylic acid copolymer L are mixed in a ratio of 1.5:1 to 3.5:1 (w/w) as release-control coating base materials, and
• weight of the methacrylic acid copolymer S and the methacrylic acid copolymer L, as the release-control coating base material, is 15 to 40% (w/w), with respect to a weight of an endothelial coated tablet.