Claims for Patent: 5,972,389

Summary for Patent: 5,972,389

Title:	Gastric-retentive, oral drug dosage forms for the controlled-release of sparingly soluble drugs and insoluble matter
Abstract:	Controlled-release oral drug dosage forms that comprise a tablet or capsule containing a plurality of particles of a solid-state drug dispersed in a swellable/erodible polymer, such as poly(ethylene oxide) are described. Once ingested, the tablet or capsule disintegrates to disperse the particles within the stomach where they imbibe water to cause them to swell and promote retention in fed-mode-induced patients. As the gastric-retained dosage form gradually erodes, the drug is released in a controlled manner to the stomach for treatment of local disorders, and to the upper gastrointestinal tract where it becomes available for absorption in a controlled and therapeutic manner. Drug-containing vesicles, such as liposomes or nanoparticles or enteric-coated drug particles, can also be delivered to the gastrointestinal tract in a controlled manner using the gastric-retentive dosage forms of the present invention.
Inventor(s):	Shell; John W. (Hillsborough, CA), Louie-Helm; Jenny (Union City, CA)
Assignee:	DepoMed, Inc. (Foster City, CA)
Application Number:	08/716,906
Patent Claims:	1. A controlled release oral drug dosage form for releasing a sparingly soluble drug into the stomach, duodenum and upper small intestine of a patient, said drug dosage form comprising: a plurality of solid particles consisting of said drug dispersed within a polymer that (i) swells unrestrained dimensionally via imbibition of water from gastric fluid to increase the size of the particles to promote gastric retention in the stomach of said patient in which the fed mode has been induced, (ii) gradually erodes over a time period of hours, said erosion commencing upon contact with said gastric fluid, and (iii) releases said drug to the stomach duodenum and upper small intestine of said patient, as a result of said erosion at a rate corresponding to said time period; wherein said polymer is poly(ethylene oxide). 2. The dosage form in accordance with claim 1 wherein the dosage form is in the form of a tablet or capsule that packages said solid particles prior to their ingestion and then dissolves upon contact with the gastric fluid to permit said solid particles to disperse in the stomach. 3. The dosage form in accordance with claim 1 wherein said poly(ethylene oxide) has a molecular weight of between about 9.times.10.sup.5 kD and 8.times.10.sup.6 kD. 4. The dosage form in accordance with claim 3 wherein said poly(ethylene oxide) has a molecular weight of between about 1.times.10.sup.6 kD and 7.times.10.sup.6 kD. 5. The dosage form in accordance with claim 1 wherein said drug is a member selected from the group consisting of nifedipine, acyclovir, alprazolam, phenytoin, carbamazepine, ranitidine, cimetidine, famotidine, clozapine, nizatidine, omeprazole, gemfibrozil, lovastatin and nitrofurantoin. 6. The dosage form in accordance with claim 1 wherein said drug is a Helicobacter pylori eradicant. 7. The dosage form in accordance with claim 6 wherein said eradicant is a member selected from the group consisting of bismuth subsalicylate, bismuth citrate, amoxicillin, tetracycline, chlarithromycin, thiamphenicol, metronidazole, omeprazole, ranitidine, cimetidine, famotidine and combinations thereof. 8. The dosage form in accordance with claim 7 wherein said eradicant is bismuth subsalicylate. 9. The dosage form in accordance with claim 8 wherein the controlled time period is about 6 to 8 hours, and the dose of said bismuth subsalicylate is 200-800 mg. 10. The dosage form in accordance with claim 1 wherein said solid particles are about 6-13 mm in length in maximum dimension prior to swelling. 11. The dosage form in accordance with claim 1 wherein said solid particles are about 7-11 mm in length in maximum dimension prior to swelling. 12. The dosage form in accordance with claim 1 wherein said solid particles are about 3-10 mm in diameter prior to swelling. 13. The dosage form in accordance with claim 1 wherein said solid particles are about 5-7 mm in diameter prior to swelling. 14. The dosage form in accordance with claim 2 wherein said dosage form is a size 0 capsule, the particles are about 5-7 mm in diameter and number about 2-3 in one capsule. 15. The dosage form in accordance with claim 9 wherein said drug is in a vesicle. 16. The dosage form in accordance with claim 15 wherein said vesicle is a member selected from the group consisting of liposomes, nanoparticles, pharmacosomes and proteinoid or amino acid microspheres. 17. The dosage form in accordance with claim 1 wherein said solid particles consist of a first drug dispersed within a first swellable/erodible polymer and a second drug dispersed within a second swellable/erodible polymer, said first and second swellable/erodible polymers exhibiting different erosion rates. 18. The dosage form in accordance with claim 17 wherein said first drug is chemically incompatible with said second drug. 19. The dosage form in accordance with claim 1 wherein said solid particles consist of particles comprising a first drug and particles comprising a second drug. 20. The dosage form in accordance with claim 1 wherein said drug is calcium carbonate, and wherein the gastric retention in the stomach and the erosion time of said solid particles assure a substantially complete dissolution of said drug in the acid environment of the stomach. 21. A controlled release oral drug dosage form for releasing a vesicle-containing drug into the stomach, duodenum, and intestinal areas which contain Peyer's patches of a patient, said dosage form comprising a plurality of solid particles consisting of said vesicle-containing drug dispersed within a polymer that (i) swells unrestrained dimensionally via imbibition of water from gastric fluid to increase the size of the particles to promote gastric retention in the stomach of said patient in which the fed mode has been induced, (ii) gradually erodes over a time period of hours, said erosion commencing upon contact with said gastric fluid, and (iii) releases said vesicle-containing drug to the stomach, duodenum, and intestinal areas which contain Peyer's patches of said patient, as a result of said erosion at a rate corresponding to said time period; wherein said polymer is poly(ethylene oxide). 22. The dosage form of claim 21 wherein said drug is soluble, but is rendered sparingly soluble when contained in said vesicle. 23. The dosage form in accordance with claim 21 wherein said vesicle is a member selected from the group consisting of a liposome, nanoparticle, nanosphere and nanocapsule. 24. The dosage form in accordance with claim 21 wherein said solid particles consist of a first drug dispersed within a first swellable/erodible polymer and a second drug dispersed within a second swellable/erodible polymer, said first and second swellable polymers exhibiting different erosion rates. 25. The dosage form in accordance with claim 24 wherein said first drug is chemically incompatible with said second drug. 26. A controlled release oral drug dosage form for releasing an enteric-coated drug into the stomach, duodenum and upper small intestine of a patient, said dosage form comprising a plurality of solid particles consisting of said enteric-coated drug dispersed within a polymer that (i) swells unrestrained dimensionally via imbibition of water from gastric fluid to increase the size of the particles to promote gastric retention in the stomach of said patient in which the fed mode has been induced, (ii) gradually erodes over a time period of hours, said erosion commencing upon contact with said gastric fluid, and (iii) releases said enteric-coated drug to the stomach, duodenum and upper small intestine of said patient, as a result of said erosion at a rate corresponding to said time period; wherein said polymer is poly(ethylene oxide). 27. The dosage form of claim 26 wherein said drug is soluble, but is rendered sparingly soluble when enteric-coated. 28. The dosage form in accordance with claim 26 wherein the enteric-coating is a member selected from the group consisting of methacrylic acid copolymer and water-based dispersions of cellulose acetate phthalate latex. 29. The dosage form in accordance with claim 26 wherein said solid particles consist of a first drug dispersed within a first swellable/erodible polymer and a second drug dispersed within a second swellable/erodible polymer, said first and second swellable polymers exhibiting different erosion rates. 30. The dosage form in accordance with claim 29 wherein said first drug is chemically incompatible with said second drug. 31. A method for delaying the passage of a sparingly soluble drug through the gastrointestinal tract of a patient, said method comprising: providing a dosage form consisting of a plurality of solid particles consisting of a solid-state drug dispersed within a polymer that (i) swells unrestrained dimensionally via imbibition of water from gastric fluid to increase the size of the particles to promote gastric retention in the stomach of said patient in which the fed mode has bean induced, (ii) gradually erodes over a time period of hours, said erosion commencing upon contact with said gastric fluid, and (iii) releases said drug to the stomach, duodenum and upper small intestine, as a result of said erosion at a rate dependent on said time period; and introducing said dosage form to said patient orally; wherein said polymer is poly(ethylene oxide). 32. The drug dosage form in accordance with claim 1 wherein the dosage form is in the form of a tablet. 33. The drug dosage form in accordance with claim 1 wherein the dosage form is in the form of a capsule.