Patent ID: 8088415

Claim:
A diffusion controlled dosage form having at least one unit providing a diffusion controlled release of Active Pharmaceutical Ingredient, the unit comprising: a powder comprising particles of release blocking-polymer and particles of release-regulating polymer, wherein the release-blocking polymer is substantially insoluble in water but is soluble at room temperature in a solvent other than water; a printed core comprising the powder and at least one Active Pharmaceutical Ingredient, wherein the powder particles are bound to each other by Active Pharmaceutical Ingredient; and a printed shell that surrounds the core, the shell comprising the powder, wherein the powder particles are bound to each other; wherein the unit provides a diffusion controlled release of Active Pharmaceutical Ingredient upon exposure to water or bodily fluid; the core has a core ratio of release-blocking polymer to release-regulating polymer in the core, the shell has a shell ratio of release-blocking polymer to release-regulating polymer in the shell, and the core ratio is substantially the same as the shell ratio; and the core comprises the same release-blocking polymer and the same release-regulating polymer as contained in the shell.