In certain embodiments, the present invention is directed to a solid controlled release dosage form comprising: a core comprising a first portion of an opioid analgesic dispersed in a first matrix material； and a shell encasing the core and comprising a second portion of the opioid analgesic dispersed in a second matrix material； wherein the opioid analgesic is selected from the group consisting of hydrocodone, pharmaceutically acceptable salts thereof, hydrates thereof, solvates thereof, and mixtures thereof； wherein the amount of opioid analgesic released from the dosage form is proportional within 20% to elapsed time from 8 to 24 hours, as measured by an in-vitro dissolution in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid without enzymes (SGF) at 37°C.
