Pharmaceutical compositions

A multi-layer composition comprising:

• a. a water-soluble core;
• b. an antagonist containing layer comprising naltrexone or a pharmaceutically acceptable salt of naltrexone coating the core;
• c. a sequestering polymer layer coating the antagonist containing layer;
• d. an agonist layer comprising morphine or a pharmaceutically acceptable salt of morphine coating the sequestering polymer layer;
• and,
• e. a controlled release layer coating the agonist layer;
• wherein the multi-layer composition sequesters at least 80% of the naltrexone or the pharmaceutically acceptable salt of naltrexone as determined at 73 hours by first placing the multi-layer composition in 500 mL of a 0.1 N HCl solution for 1 hour at 37° C. using USP paddle method, 100 rotations per minute, and then placing the multi-layer composition in 500 mL of a pH 7.5, 0.05 M phosphate buffer, for 72 hours at 37° C. using USP paddle method, 100 rotations per minute, and then determining the amount of the naltrexone or the pharmaceutically acceptable salt thereof sequestered;
• and
• wherein one of the following conditions are met:
• i) the agonist layer comprises sodium chloride;
• or
• ii) the multilayer composition further comprises, immediately beneath the agonist layer, an osmotic pressure regulating agent layer comprising sodium chloride.