Methods of treatment using a gastric retained gabapentin dosage form

Abstract

A method of treatment for epilepsy and other disease states is described, which comprises delivery of gabapentin in a gastric retained dosage form.

1 . A dosage form, comprising:
 a core comprising gabapentin, and   a semipermeable membrane surrounding the core, the semipermeable membrane comprising a plasticizer and being permeable to a fluid in an environment of use and substantially impermeable to unsolubilized gabapentin,   wherein the dosage form has a size to promote retention in the upper gastrointestinal tract of a subject in a fed mode for a period of about 5 hours, and wherein at least about 80 wt % of the gabapentin is released from the dosage form in about 5-12 hours via controlled release through the semipermeable membrane.   
     
     
         2 . The dosage form of  claim 1 , wherein the core comprises about 300 mg gabapentin. 
     
     
         3 . The dosage form of  claim 1 , wherein the core comprises about 600 mg gabapentin. 
     
     
         4 . The dosage form of  claim 1 , wherein the semipermeable membrane comprises a material selected from the group consisting of cellulose esters, cellulose ethers, polyalkylene oxides, polyvinyl alcohol, and polyvinylpyrrolidone. 
     
     
         5 . The dosage form of  claim 4 , wherein the cellulose ether is selected from the group consisting of ethyl cellulose, hydroxyethylcellulose, hydroxypropylcellulose, and methylcellulose. 
     
     
         6 . The dosage form of  claim 1 , wherein the plasticizer is selected from esters and fatty acids. 
     
     
         7 . The dosage form of  claim 1 , wherein the dosage form further comprises a second therapeutic agent selected from the group consisting of a hydantoin, an iminostilbene, a valproate, a phenyltriazine, a barbiturate, a dexoybarbiturate, a benzodiazepine, a carbamate, an anticonvulsant other than gabapentin, a tricyclic antidepressant, levadopa, carbidopa, an opioid, lithium, carbamazepine, valproate, trifluoperazine, clonazepam, risperidone, lorazepam, venlafaxine, clozapine, olanzapine, a neuroleptic, a serotonin reuptake inhibitor, buproprion, nefadone, venlaxatine, nefadone, diazepam, oxazepam, a dopaminergic agent, clonazepam, a triptan and ergotamine. 
     
     
         8 . A method for treating epilepsy, psychiatric disorders, neuropathic pain or movement disorder, comprising
 administering an extended release dosage form, comprising:   a core comprising gabapentin, and   a semipermeable membrane surrounding the core, the semipermeable membrane comprising a plasticizer and being permeable to a fluid in an environment of use and substantially impermeable to unsolubilized gabapentin,   wherein the dosage form is formulated to have a size to promote retention in the upper gastrointestinal tract of a subject in a fed mode for a period of about 5 hours, and wherein at least about 80 wt % of the gabapentin is released from the dosage form in about 5-12 hours via controlled release through the semipermeable membrane.   
     
     
         9 . The method according to  claim 8 , wherein the dosage form provides for bioavailability of gabapentin at a level greater than or equal to 80% of that provided by an equal dose of gabapentin released by the immediate release dosage form as measured by the plasma AUC inf . 
     
     
         10 . The method according to  claim 9 , wherein the gabapentin is released into the upper gastrointestinal tract over a period of about 5-12 hours at a rate sufficient to achieve a lower maximum plasma concentration (C max ) compared to an equal dose of gabapentin provided by an immediate release dosage form.