A dosage form comprising a plurality of pellets, the pellets comprising a core element comprising morphine sulfate, a filler and a binder, wherein the morphine sulfate, calculated as the anhydrous form, comprises about 50 wt% to about 85 wt% of the total weight of the core element and a controlled-release coating disposed on at least a portion of the core element, the coating comprising an insoluble matrix polymer which is insoluble at pH 1 to 7.5 an enteric polymer which is insoluble at pH 1 to 4 and soluble at pH 6 to 7.5 and an acid soluble polymer which is soluble at a pH of 1 to 4, wherein the ratio of the acid soluble polymer to the enteric polymer is 1.45:1 to 2.5:1 on a weight basis, wherein the Cmax of the dosage form differs by less than 20% when administered to a mammalian subject in the fed state compared to the fasted state. Also included are methods of increasing patient compliance by administering the disclosed dosage form to a mammalian subject.
