A zero-order controlled release pharmaceutical dosage form for oral administration

A zero-order release pharmaceutical dosage form for oral administration to a patient comprising a core tablet sheathed in an annular body of compressed powder or granular material is provided. A preferred embodiment of the zero-order release pharmaceutical dosage form is a solid pharmaceutical dosage form which reduces contact of the active ingredient in solid form with the mucosa lining the gastrointestinal tract, which is particularly advantageous for delivering an ulcerative drug. A process for making the zero-order release pharmaceutical dosage form is also provided. Particularly disclosed is a pharmaceutical dosage form for oral administration to a patient comprising a core tablet having two axial surfaces containing an active ingredient, at least 19% of hydrogel excipient, and a non-hydrogel excipient, the core being sheathed in an annular body, itself having two axial surfaces, of compressed powder or granular material, whereby the annular body controls the drug-releasing surface area of the two axial surfaces of the core tablet to between 0.4 mm2 and 265 mm2 and whereby the dosage form releases the active ingredient from the core tablet at a rate in the range of from 3% per hour to 12% per hour over a period of seven hours or more.