Colon targeted drug delivery

A pharmaceutical composition for oral administration comprising:

• a therapeutic agent core comprising porous activated carbon particles having substantially spherical particles that have a minimum average particle diameter of at least 0.005 mm and a maximum average particle diameter of less than 1.5 mm;
• and
• a plurality of degradable layers for exposing a surface of the therapeutic agent core, wherein there is an inner degradable layer and an outer degradable layer;
• wherein the outer layer comprises an acrylic based polymer selected from the group consisting of (a) methacrylic acid copolymer S or (b) a co-polymer of methacrylic acid and methyl methacrylate, and further wherein the outer layer comprises between about 20-40% weight of the acrylic polymer based on the therapeutic core, and
• wherein the inner layer comprises a polymer selected from the group consisting of (a) ethyl cellulose or (b) poly(ethyl acrylate co-methyl methacrylate) co-polymer.