Composition for Administering an NMDA Receptor Antagonist to a Subject

1 . An extended release pharmaceutical composition in tablet or capsule form for oral administration to a human subject in need of amantadine therapy consisting of:

a. amantadine, or a pharmaceutically acceptable salt thereof;

b. one or more excipients, wherein at least one of said excipients modifies the release of the amantadine from the composition; and

c. if the composition is in capsule form, a capsule;

wherein the composition has an in vitro dissolution profile in water that is less than 5% in 15 minutes, less than 10% in 30 minutes, 40% to 80% in 6 hours, and greater than or equal to 90% in 12 hours as measured using a USP type II (paddle) dissolution system at 50 rpm, at a temperature of 37±0.5° C.;

and wherein the composition is designed for once daily administration of a therapeutically effective amount of amantadine, or a pharmaceutically acceptable salt thereof.

2 . The composition of claim 1 , wherein the rate of release of the amantadine from said composition is less than 10% of the rate for an IR formulation of amantadine over the first hour.

3 . The composition of claim 1 or 2 , wherein the therapeutically effective amount of the amantadine, or the pharmaceutically acceptable salt thereof, is 25 mg to 500 mg.

4 . The composition of claim 1 or 2 , wherein the therapeutically effective amount of the amantadine, or the pharmaceutically acceptable salt thereof, is 200 mg to 500 mg.

5 . The composition of claim 1 or 2 , wherein the therapeutically effective amount of the amantadine, or the pharmaceutically acceptable salt thereof, is 300 mg to 500 mg.

6 . The composition of claim 1 or 2 , wherein said composition has an in vitro dissolution of at least 70% at 10 hours in a dissolution media having a pH of 1.2 as measured using a USP type II (paddle) dissolution system at 50 rpm, at a temperature of 37±0.5° C.

7 . The composition of claim 1 or 2 , wherein said composition has an in vitro dissolution of at least 80% at 10 hours in a dissolution media having a pH of 1.2 as measured using a USP type II (paddle) dissolution system at 50 rpm, at a temperature of 37±0.5° C.