Patent ID: 7658939

Claim:
An opioid antagonist composition comprising an inert core, a first layer and a second layer, the first layer being between the core and the second layer, the first layer consisting of the opioid antagonist, and the second layer comprising a hydrophobic material, wherein the hydrophobic material sequesters the opioid antagonist such that an amount of the antagonist released from the composition which has been administered intact is bioequivalent to 0.125 mg naltrexone or less, based on the in-vitro dissolution at 1 hour of the composition in 900 ml of Simulated Gastric Fluid using a USP Type II (paddle) apparatus at 75 rpm at 37° C., and less than 15% by weight of the opioid antagonist is released within 36 hours from the intact composition, based on the in-vitro dissolution in a dissolution bath, and the composition is free from an opioid agonist.