Composition for Administering an NMDA Receptor Antagonist to a Subject

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.