Intranasal compositions for treatment of neurological and neurodegenerative diseases and disorders

1. A sustained-release aqueous intranasal formulation consisting of:

rivastigmine tartrate in an amount of from about 0.5% to about 15% by weight of the total formulation;

citric acid monohydrate in an amount to provide the formulation with a pH in the range of about 3 to 6;

polyvinyl pyrrolidone in an amount selected to improve adherence of the formulation to the nasal mucosa without adversely affecting administration of the formulation as an intranasal spray, said amount being from about 0.1% to about 2% by weight of the total formulation;

ethanol;

benzyl alcohol;

I-carveol; and

water.

2. An aqueous formulation according to claim 1 wherein the pH modifying agent is present in an amount of from about 0.01% to about 2% by weight of the total formulation.

3. A method of treating a neurodegenerative disease in a mammal, comprising administering an intranasal formulation according to claim 1 to a mammal in need thereof, wherein the neurodegenerative disease is selected from Alzheimer's disease, Parkinson's disease and cognitive dysfunction syndrome.

4. The method according to claim 3 wherein the absolute bioavailability (F) of rivastigmine is equivalent to at least 60%.

5. The method according to claim 3 , wherein the rivastigmine plasma concentration (C max ) of the mammal is at least about 5000 pg/mL.

6. The method according to claim 3 , wherein the therapeutic rivastigmine plasma concentration (C max ) of the mammal is in the range of about 2000 pg/mL to about 20,000 pg/mL.

7. The method according to claim 5 wherein the therapeutic rivastigmine plasma concentration is maintained for a duration of at least 4 hours (T maint ).

8. The method according to claim 3 wherein the intranasal administration is associated with a reduced incidence of side effects.