Patent ID: 6960357

Claim:
A dissolution-controlled chemical delivery device providing substantially controlled-release of at least one active ingredient into a gastrointestinal fluid throughout a substantial portion of a delivery period which composition comprises: (i) a shaped core (a) having at least one planar dissolution-controlled release face, (b) comprising a compressed mixture containing less than 90% (w/w) of the active ingredient homogeneously mixed with at least one dissolution regulator operable to release the active ingredient from said release face wherein a release rate is determined by a surface area and rate of erosion of the release face, and optionally (c) having a score circumscribed on the surface to secure a coating; (ii) a mechanically strong granule compression coating surrounding and adhering to said core except the release face(s), said coating comprising an insoluble polymer selected from the group consisting of ethyl cellulose, cellulose acetate, cellulose acetate butyrate, polyvinyl alcohol, polyvinyl acetate and a methacrylic acid copolymer, optionally at least one pore-forming element, and at least one pH sensitive element selected from the group consisting of cellulose acetate phthalate, hydroxypropyl methylcellulose phthalate, polyvinylacetate phthalate and polymethacrylate operable to permit disintegration of the coating after release of said active ingredient is completed, wherein said coating does not alter a release rate of the active ingredient.