Claims for Patent: 8,309,122

Summary for Patent: 8,309,122

Title:	Oxymorphone controlled release formulations
Abstract:	The invention pertains to a method of relieving pain by administering a controlled release pharmaceutical tablet containing oxymorphone which produces a mean minimum blood plasma level 12 to 24 hours after dosing, as well as the tablet producing the sustained pain relief.
Inventor(s):	Kao; Huai-Hung (Syosset, NY), Baichwal; Anand R. (Wappingers Falls, NY), McCall; Troy (Smyma, GA), Lee; David (Chadds Ford, PA)
Assignee:	Endo Pharmaceuticals Inc. (Chadds Ford, PA)
Application Number:	11/680,432
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 8,309,122
Patent Claims:	1. An analgesically effective controlled release pharmaceutical composition with a twelve hour dosing interval in the form of a tablet, comprising oxymorphone or a pharmaceutically acceptable salt thereof as the sole active ingredient in the tablet, and a controlled release delivery system comprising at least one pharmaceutical excipient, wherein upon placement of the composition in an in vitro dissolution test comprising USP Paddle Method at 50 rpm in 500 ml media having a pH of 1.2 to 6.8 at 37.degree. C., about 15% to about 50%, by weight, of the oxymorphone or salt thereof is released from the tablet at about 1 hour in the test. 2. The pharmaceutical composition of claim 1 wherein about 45% to about 80%, by weight, of the oxymorphone or salt thereof is released from the tablet at about 4 hours in the test. 3. The pharmaceutical composition of claim 1 wherein at least about 80%, by weight, of the oxymorphone or salt thereof is released from the tablet at about 10 hours in the test. 4. The pharmaceutical composition of claim 1 wherein the controlled release delivery system comprises a hydrophilic material that forms a gel upon exposure to gastrointestinal fluid. 5. The pharmaceutical composition of claim 1 wherein the controlled release delivery system comprises a heteropolysaccharide and an agent capable of cross-linking the heteropolysaccharide in presence of gastrointestinal fluid. 6. The pharmaceutical composition of claim 5 wherein the heteropolysaccharide and the agent capable of cross-linking the heteropolysaccharide are present in a weight ratio of about 1:3 to about 3:1. 7. The pharmaceutical composition of claim 5 wherein the heteropolysaccharide comprises xanthan gum or deacylated xanthan gum. 8. The pharmaceutical composition of claim 5 wherein the agent capable of cross-linking the heteropolysaccharide comprises a homopolysaccharide gum. 9. The pharmaceutical composition of claim 8 wherein the homopolysaccharide gum comprises locust bean gum. 10. The pharmaceutical composition of claim 1 wherein the controlled release delivery system further comprises a hydrophobic polymer. 11. The pharmaceutical composition of claim 10 wherein the hydrophobic polymer comprises an alkylcellulose. 12. The pharmaceutical composition of claim 8 further comprising a cationic cross-linking agent. 13. The pharmaceutical composition of claim 12 wherein the cationic cross-linking agent is selected from calcium sulfate, sodium chloride, potassium sulfate, sodium carbonate, lithium chloride, tripotassium phosphate, sodium borate, potassium bromide, potassium fluoride, sodium bicarbonate, calcium chloride, magnesium chloride, sodium citrate, sodium acetate, calcium lactate, magnesium sulfate, sodium fluoride, and combinations thereof. 14. The pharmaceutical composition of claim 13 wherein the cationic cross-linking agent is present in an amount of about 0.5% to about 16%, by weight of the composition. 15. The pharmaceutical composition of claim 5 wherein the weight ratio of heteropolysaccharide to oxymorphone or pharmaceutically acceptable salt thereof is about 10:1 to about 1:10. 16. The pharmaceutical composition of claim 1 wherein oxymorphone or pharmaceutically acceptable salt thereof is present in an amount of about 5 mg to about 80 mg. 17. The pharmaceutical composition of claim 5 wherein the controlled release delivery system comprises about 10% to about 99% of a gelling agent comprising a heteropolysaccharide gum and a homopolysaccharide gum, about 1% to about 20% of a cationic crosslinking agent, and about 0% to about 89% of other ingredients which qualify as an inert pharmaceutical diluent, by total weight of the controlled release delivery system. 18. A method of treating pain in a subject in need thereof, the method comprising administering to the subject the pharmaceutical composition of claim 1 comprising about 5 mg to about 80 mg of oxymorphone or pharmaceutically acceptable salt thereof. 19. An analgesically effective controlled release pharmaceutical composition with a twelve hour dosing interval in the form of a tablet, comprising oxymorphone or pharmaceutically acceptable salt thereof as the sole active ingredient in the tablet and a controlled release delivery system comprising a hydrophilic material that forms a gel upon exposure to gastrointestinal fluid, wherein upon placement of the composition in an in vitro dissolution test comprising USP Paddle Method at 50 rpm in 500 ml media having a pH of 1.2 to 6.8 at 37.degree. C., about 15% to about 50%, by weight, of the oxymorphone or salt thereof is released from the composition at about 1 hour in the test, about 45% to about 80%, by weight, of the oxymorphone or salt thereof is released from the composition at about 4 hours in the test, and at least about 80%, by weight, of the oxymorphone or salt thereof is released from the composition at about 10 hours in the test. 20. The method of claim 18 wherein upon oral administration of the composition the oxymorphone AUC.sub.(o-inf) is no more than 20% higher when the composition is administered to the subject under fed as compared to fasted conditions.