Pharmaceutical compositions

A pharmaceutical composition for oral administration comprising: a) a sequestering subunit comprising: a water-soluble core; a first layer comprising naltrexone, or a pharmaceutically acceptable salt thereof or a combination thereof; a second layer comprising a sequestering polymer, a sodium lauryl sulfate and talc, wherein the talc is present in an amount greater than about 66% and less than about 150% of the amount of sequestering polymer on a weight / weight basis; and an optional third layer comprising an osmotic pressure regulating agent selected from hydroxypropylmethylcellulose and sodium chloride, bromide or iodide, or a combination thereof; and b) an opioid agonist selected from morphine, oxycodone, hydrocodone, hydromorphone, dihydrocodeine, codeine, dihydromorphine or buprenorphine, or a pharmaceutically acceptable salt thereof or a combination thereof; wherein the sequestering subunit sequesters at least 80% of the naltrexone or the pharmaceutically acceptable salt thereof, as determined at 72 hours by the dissolution test procedures of USP26 <711>, for example, by first placing the Pharmaceutical composition in 500 ml of a 0.1 N HCl solution for 1 hour at 37 ° C, using the USP blade method, 100 rotations per minute, and then placing the multilayer composition in 500 ml of a phosphate buffer. , 05 M, pH 7.5, for 72 hours at 37 ° C, using the USP blade procedure, 100 rotations per minute, and then determining the amount of the naltrexone or the pharmaceutically acceptable salt sequestered.