Encased tamper resistant controlled release dosage forms

A solid controlled release dosage form comprising:

• a core comprising a first portion of hydrocodone or a pharmaceutically acceptable salt thereof dispersed in a first matrix material;
• and
• a shell encasing the core and comprising a second portion of the hydrocodone or pharmaceutically acceptable salt thereof dispersed in a second matrix material;
• wherein the first matrix material, the second matrix material, or both the first and second matrix material comprises polyethylene oxide having an average molecular weight from about 300,000 to about 10,000,000, wherein the dosage form is cured at a temperature of at least 60 ° C. for at least 1 minute;
• wherein the amount of hydrocodone or pharmaceutically acceptable salt thereof released from the dosage form at 2 hours is less than about 25%, at 4 hours is from about 10% to about 30%, at 8 hours is from about 20% to about 60%, at 12 hours is from about 40% to about 90%, and at 18 hours is greater than about 70%;
• wherein the dosage form can be flattened without breaking, wherein the thickness of the dosage form after flattening corresponds to no more than about 20% of the thickness of the dosage form before flattening;
• and
• the amount of hydrocodone or pharmaceutically acceptable salt thereof released at 0.5 hour from a flattened dosage form deviates no more than about 20% points from a non-flattened dosage form 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.