Compositions for the treatment of cns-related conditions

A solid pharmaceutical composition in a unit dosage form for once daily, oral administration comprising:

• a) a first drug selected from the group consisting of memantine and a pharmaceutically acceptable salt thereof in an amount of 22.5 mg to 33.75 mg;
• b) a second drug selected from the group consisting of donepezil and a pharmaceutically acceptable salt thereof in an amount of 1 mg to 10 mg;
• and
• c) at least one excipient that modifies release of said first drug to provide an extended release form of said first drug,
• wherein oral administration of a dose of said pharmaceutical composition to a human subject of a fasted single dose human pharmacokinetic study provides a plasma concentration profile of memantine characterized by a change in plasma concentration of memantine as a function of time (dC/dT) that is less than about 50% of a change in plasma concentration of memantine as a function of time (dC/dT) determined for oral administration of an equal dose of said first drug in an immediate release form to a human subject of a fasted single dose human pharmacokinetic study,
• wherein the dC/dT for both said pharmaceutical composition and said immediate release form of said first drug are determined in a time period between 0 hours and 6 hours of administration of said pharmaceutical composition and said immediate release form to a human subject in the same concurrent fasted single dose human pharmacokinetic study.

A solid pharmaceutical composition in a unit dosage form for once daily, oral administration comprising:

• a) a first drug selected from the group consisting of memantine and a pharmaceutically acceptable salt thereof in an amount of 22.5 mg to 33.75 mg;
• b) a second drug selected from the group consisting of donepezil and a pharmaceutically acceptable salt thereof in an amount of 1 mg to 10 mg;
• and
• c) at least one excipient that modifies release of said first drug to provide an extended release form of said first drug,
• wherein oral administration of a dose of said pharmaceutical composition to a human subject of a fasted single dose human pharmacokinetic study provides a plasma concentration profile of memantine characterized by a change in plasma concentration of memantine as a function of time (dC/dT) per mg of said first drug that is less than about 50% of a change in plasma concentration of memantine as a function of time (dC/dT) per mg of said first drug determined for oral administration of an immediate release form of said first drug to a human subject of a fasted single dose human pharmacokinetic study,
• wherein the dC/dT per mg for both said pharmaceutical composition and said immediate release form of said first drug are determined in a time period between 0 hour to 6 hours of administration of said pharmaceutical composition and said immediate release form to a human subject in the same concurrent fasted single dose human pharmacokinetic study.