Claims for Patent: 6,287,599

Summary for Patent: 6,287,599

Title:	Sustained release pharmaceutical dosage forms with minimized pH dependent dissolution profiles
Abstract:	A pharmaceutical composition comprising at least one pharmaceutically active agent that is pH dependent, at least one non-pH dependent sustained release agent, and at least one pH dependent agent that increases the dissolution rate of the at least one pharmaceutically active agent at a pH in excess of 5.5. Such compositions have minimized pH-dependent dissolution profiles or pH-independent dissolution profiles.
Inventor(s):	Burnside; Beth A. (Brookeville, MD), Chang; Rong-Kun (Rockville, MD), Guo; Xiaodi (Derwood, MD)
Assignee:	Shire Laboratories, Inc. (Rockville, MD)
Application Number:	09/741,548
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 6,287,599
Patent Claims:	1. A pharmaceutical composition, comprising: (a) at least one pharmaceutically active agent that is pH dependent: (b) at least one non-pH dependent sustained release agent; and (c) at least one pH dependent agent that increases the rate of release of said at least one pharmaceutically active agent from the tablet at a pH in excess of 5.5. 2. The composition of claim 1 wherein said at least one pH dependent agent is at least one polymer that swells at a pH in excess of 5.5. 3. The composition of claim 1 wherein said at least one pH dependent agent is at least one enteric agent. 4. The composition of claim 1 wherein said at least one pH dependent agent is at least one agent that increases the solubility of said at least one pharmaceutically active agent at a pH of greater than 5.5. 5. The composition of claim 1 wherein said at least one pharmaceutically active agent is selected from the group consisting of guanfacine hydrochloride, anagrelide, guanethidine monosulfate, quanadrel sulfate, resirpine, propanolol, metoprolol, atenolol, timolol, erythromycin, clonidine, chlorpheniramine, bromopheniramine, diltiazem, and scopolamine. 6. The composition of claim 5 wherein said at least one pharmaceutically active agent guanfacine hydrochloride. 7. The composition of claim 5 wherein said at least one pharmaceutically active agent is anagrelide hydrochloride. 8. The composition of claim 1 wherein said non-pH dependent sustained release agent is selected from the group consisting of ethylcellulose, cellulose acetate, vinyl acetate/vinyl chloride copolymers, acrylate/methacrylate copolymers, polyethylene oxide, hydroxypropyl methylcellulose, carageenan, alginic acid and salts thereof, hydroxyethyl cellulose, hydroxypropyl cellulose, karaya gum, acacia gum, trgacanth gum, locust bean gum, guar gum, sodium carboxymethyl cellulose, methyl cellulose, beeswax, carnauba wax, cetyl alcohol, hydrogenated vegetable oils, and stearyl alcohol. 9. The composition of claim 2 wherein said at least one polymer that swells at a pH in excess of 5.5 is selected from the group consisting of acrylic acid copolomers, sodium alginate, carrageenan, alginic acid, pectin, and sodium carboxymethyl cellulose. 10. The composition of claim 3 wherein said at least one enteric agent is selected from the group consisting of cellulose acetate phthalate, hydroxypropyl methylcellulose phthalate, polvinyl acetate phthalate, methacrylic acid copolymers, cellulose acetate trimellitate, hydroxypropyl methylcellulose acetate, succinate, shellac, and zein. 11. The composition of claim 4 wherein said at least one agent that increase the solubility of said at least one pharmaceutically active agent at a pH greater than 5.5 is at least one organic acid. 12. The composition of claim 11 wherein said at least one organic acid is selected from the group consisting of citric acid, fumaric acid, tartaric acid, adipic acid, glucono delta-lactone, and malic acid. 13. The composition of claim wherein said pH-dependent agent that increase the rate of release of the at least one pharmaceutically active agent from the tablet at a pH in excess of 5.5 is an agent that maintains an acidic microenvironment in the composition. 14. The composition of claim 12 wherein said organic acid is fumaric acid. 15. The composition of claim 1 and further comprising a binding agent. 16. The composition of claim 15 wherein said binding agent is selected from the group consisting of polyvinyl pyrrolidone, starch, methylcelluose, hydroxypropyl methylcelluose, carboxymethyl cellulose, sucrose solution, dextrose solution, acacia, tragacanth,and locust bean gum. 17. The composition of claim 16 wherein said binder is hydroxypropyl methylcellulose. 18. The composition of claim 1 wherein said pharmaceutically active agent is present in the composition in an amount of from about 0.1 wt. % to about 70 wt .%. 19. The composition of claim 18 wherein said pharmaceutically active agent is present in the composition in an amount of from about 1 wt. % to about 40 wt. %. 20. The composition of claim 1 wherein said non-pH-dependent sustained release agent is present in the composition in an amount of from about 5 wt. % to about 50 wt. %. 21. The composition of claim 20 wherein said non-pH-dependent sustained release agent is present in the composition in an amount of from about 10 wt. % to about 30 wt. %. 22. The composition of claim 1 wherein said at least one pH-dependent agent is present in the composition in an amount of from about 0.5 wt. % to about 40 wt. %. 23. The composition of claim 22 wherein said at least one pH-dependent agent is present in the composition in an amount of from about 1 wt. % to about 20 wt. %. 24. The composition of claim 8 wherein said non-pH-dependent sustained release agent is ethylcellulose. 25. The composition of claim 8 wherein said non-pH-dependent sustained release agent is hydroxypropyl methylcellulose. 26. The composition of claim 8 wherein said non-pH-dependent sustained release agent is an acrylate/methacrylate copolymer. 27. The composition of claim 8 wherein said non-pH-dependent sustained release agent is polyethylene oxide. 28. The composition of claim 9 wherein said at least one polymer that swells at a pH in excess of 5.5 is sodium alginate. 29. The composition of claim 10 wherein said at least one enteric agent is a methacrylic acid copolymer. 30. The composition of claim 1 wherein said composition is in the form of a tablet.