Delayed release oral pharmaceutical composition

A delayed-release formulation, comprising a plurality of particles, wherein each particle comprises:

• (a) an inert core, in an amount of 10-20 wt % of the particle;
• (b) a mesalamine layer applied to the surface of the inert core, wherein the mesalamine layer is in an amount of 40-65 wt % of the particle and comprises mesalamine in an amount of 80-99 wt % of the mesalamine layer;
• (c) a hyaluronan layer applied to the surface of the mesalamine layer, wherein the hyaluronan layer is in an amount of 3-15 wt % of the particle and comprises a high molecular weight hyaluronic acid or a pharmaceutically-acceptable salt thereof and a low molecular weight hyaluronic acid or a pharmaceutically-acceptable salt thereof in a ratio of 5:1 to 1:5, and the total hyaluronic acid or a pharmaceutically-acceptable salt is in an amount of 51-70 wt % of the hyaluronan layer;
• and
• (d) an isolation layer, applied to the surface of the hyaluronan layer, and comprising one or more copolymers selected from the group consisting of a methacrylic acid-methyl methacrylate copolymer, methacrylic acid-methacrylate copolymer, and a methacrylic acid-ethylacrylate copolymer;
• and
• (e) an enteric coating layer, applied to the surface of the isolation layer and comprising one or more copolymers selected from the group consisting of a methyl acrylate-methyl methacrylate-methacrylic acid copolymer, a methacrylic acid-methyl methacrylate copolymer, a methacrylic acid-ethyl acrylate copolymer, and a methacrylic acid-ethyl acetate copolymer, wherein the combined amount of the isolation layer and the enteric coating layer is 15-30 wt % of the particle.