Claims for Patent: 8,192,756

Summary for Patent: 8,192,756

Title:	Gastric retained gabapentin dosage form
Abstract:	A method of treatment for epilepsy and other disease states is described, which comprises the delivery of gabapentin in a gastric retained dosage form.
Inventor(s):	Berner; Bret (Half Moon Bay, CA), Hou; Sui Yuen Eddie (Foster City, CA), Gusler; Gloria M (Cupertino, CA)
Assignee:	Depomed, Inc. (Menlo Park, CA)
Application Number:	13/111,575
Patent Claims:	1. A dosage form, comprising: comprising from 100 mg to 4800 mg of therapeutically effective amount of gabapentin or pharmaceutically acceptable salt thereof, dispersed in a single matrix wherein the matrix comprises at least one swellable hydrophilic polymer that swells unrestrained dimensionally by imbibing water to increase its size to promote gastric retention of the dosage form in the stomach in a fed mode, wherein upon once-daily or twice-daily ingestion of the dosage form gabapentin is released from the matrix over a period of at least five hours wherein at least 40 wt% of the gabapentin is retained in the matrix one hour after administration, and wherein the gabapentin is released at a rate sufficient to achieve a lower maximum plasma concentration (C.sub.max) compared to an equal dose of gabapentin provided by an immediate release dosage form, and without loss in bioavailability as measured by the area under the curve (AUC.sub.infinity) as compared to the bioavailability which is achieved from an immediate release dosage form comprising the same dose of gabapentin. 2. The dosage form of claim 1, wherein the time to reach maximum plasma concentration is longer relative to the time to reach maximum plasma concentration from an immediate release dosage form comprising the dose of gabapentin. 3. The dosage form of claim 2, wherein the time to reach maximum plasma concentration is at least 5.6 hours .+-.34.9%. 4. The dosage form of claim 1, wherein a maximum plasma concentration (C.sub.max) of at least about 3 .mu.g/mL is achieved. 5. The dosage form of claim 1, comprising a dose of gabapentin of between about 300-600 mg. 6. A method of treating a condition responsive to a therapeutic dose of gabapentin, comprising: orally administering once-daily or twice daily a dosage form comprising between about 100 mg to about 4800 mg of gabapentin or pharmaceutically acceptable salt thereof, dispersed in a single matrix, wherein the matrix comprises at least one swellable hydrophilic polymer that swells unrestrained dimensionally by imbibing water to increase its size to promote gastric retention of the dosage form in the stomach in a fed mode, wherein upon once-daily or twice daily ingestion of the dosage form gabapentin is released from the matrix over a period of at least five hours wherein at least 40 wt% of the gabapentin is retained in the matrix one hour after administration, and whereby the dosage form releases gabapentin at a rate sufficient to achieve a lower maximum plasma concentration (C.sub.max) compared to an equal dose of gabapentin provided by an immediate release dosage form, and without loss in bioavailability as measured by the area under the curve (AUC.sub.infinity) as compared to the bioavailability which is achieved from an immediate release dosage form comprising the same dose of gabapentin. 7. The method of claim 6, wherein the time to reach maximum plasma concentration is longer relative to the time to reach maximum plasma concentration from an immediate release dosage form comprising the dose of gabapentin. 8. The method of claim 6, wherein the time to reach maximum plasma concentration is at least 5.6 hours .+-.34.9%. 9. The method of claim 6, wherein a maximum plasma concentration (C.sub.max) of at least about 3 .mu.g/mL is achieved. 10. The method of claim 6, wherein the condition is pain. 11. The method of claim 6, wherein the condition is neuropathic pain. 12. The dosage form of claim 1, further comprising an immediate release coating. 13. The dosage form of claim 12, wherein said coating comprises a second drug. 14. The dosage form of claim 13, wherein said second drug is gabapentin. 15. A dosage form, comprising: comprising from 100 mg to 4800 mg of therapeutically effective amount of gabapentin or pharmaceutically acceptable salt thereof, dispersed in a single matrix, wherein the matrix comprises at least one swellable hydrophilic polymer that swells unrestrained dimensionally by imbibing water to increase its size to promote gastric retention of the dosage form in the stomach in a fed mode, wherein upon once-daily or twice-daily ingestion of the dosage form gabapentin is released from the matrix over a period of at least five hours wherein at least 40 wt% of the gabapentin is retained in the matrix one hour after administration. 16. The dosage form of claim 15, further comprising an immediate release coating. 17. The dosage form of claim 16, wherein said coating comprises a second drug. 18. The dosage form of claim 17, wherein said second drug is gabapentin.