An oral drug delivery composition includes a sustained release component which includes a corticosteroid drug and which is contained within a capsule that has been treated so that the sustained release component is predominately released from the capsule in the intestine following oral administration. A drug delivery composition for delivering a corticosteroid drug to the intestine also includes: (a) a sustained release component comprising a corticosteroid drug, an alkali-containing ethylcellulose material and an acid； and (b) a delayed release component which substantially prevents release of the sustained release component until the composition reaches the intestine following oral administration. The compositions of the invention are useful for treating inflammatory diseases of the gastrointestinal tract, such as Crohn's disease and ulcerative colitis, and for treating glomerulonephritis.
