PHARMACEUTICAL COMPOSITIONS OF DONEPEZIL HAVING SPECIFIC IN VITRO DISSOLUTION PROFILE OR PHARMACOKINETICS PARAMETERS

1 . A timed release pharmaceutical composition comprising donepezil, wherein the single dose AUC (14-22) of the said composition administered in the morning is about 5% to about 30% less than the single dose AU 2-10) of an immediate release composition of donepezil administered in the night, wherein both the compositions have equivalent dose of donepezil.

2 . The timed release pharmaceutical composition according to claim 1 , wherein the said composition provides reduced incidence of insomnia and nightmares.

3 . The timed release pharmaceutical composition according to claim 1 , wherein the said composition shortens the titration period required for donepezil administration.

4 . The timed release pharmaceutical composition according to claim 1 , wherein the said composition shortens the titration period required for donepezil administration by two to four weeks.

5 . The timed release pharmaceutical composition according to claim 1 , wherein the said composition is used to treat a patient suffering from a disease or a condition characterized by symptoms of dementia and/or cognitive impairments.

6 . The timed release pharmaceutical composition according to claim 1 , wherein the said composition is used to treat a patient suffering from mild, moderate or severe Alzheimer's disease.

7 . A timed release pharmaceutical composition comprising donepezil, wherein the steady state AUC (14.22 of the said composition administered in the morning is about 5% to about 25% less than the steady state AUC (2-10) of an immediate release composition of donepezil administered in the night, wherein both the compositions have the same dose of donepezil and are administered orally.

8 . The timed release pharmaceutical composition according to claim 7 wherein the said composition provides reduced incidence of insomnia and nightmares.

9 . The timed release pharmaceutical composition according to claim 7 , wherein the said composition shortens the titration period required for donepezil administration.

10 . The timed release pharmaceutical composition according to claim 7 , wherein the said composition shortens the titration period required for donepezil administration by two to four weeks.

11 . The timed release pharmaceutical composition according to claim 7 wherein the said composition is used to treat a patient suffering from a disease or a condition characterized by symptoms of dementia and/or cognitive impairments.

12 . The timed release pharmaceutical composition according to claim 7 , wherein the said composition is used to treat a patient suffering from mild, moderate or severe Alzheimer's disease.

13 . A timed release pharmaceutical composition comprising donepezil, wherein the single dose AUC (7_io) of the said composition when administered in the morning is about 25% to about 85% more than the single dose AUC(i9-22) of an immediate release composition of donepezil administered in the night, wherein both the compositions have equivalent dose of donepezil.

14 . The timed release pharmaceutical composition according to claim 13 , wherein the said composition provides reduced incidence of sundowning syndrome.

15 . The timed release pharmaceutical composition according to claim 13 , wherein the said composition is used to treat a patient suffering from a disease or a condition characterized by symptoms of dementia and/or cognitive impairments.

16 . The timed release pharmaceutical composition according to claim 13 , wherein the said composition is used to treat a patient suffering from mild, moderate or severe Alzheimer's disease.

17 . A timed release pharmaceutical composition comprising donepezil, wherein the steady state AUC (7-10) of the said composition when administered in the morning is about 100% to about 50% more than the steady state AUC (19-22 of an immediate release composition of donepezil administered in the night, wherein both the compositions have the same dose of donepezil and are administered orally.

18 . The timed release pharmaceutical composition according to claim 17 , wherein the said composition provides reduced incidence of sundowning syndrome.

19 . The timed release pharmaceutical composition according to claim 17 , wherein the said composition is used to treat a patient suffering from a disease or a condition characterized by symptoms of dementia and/or cognitive impairments.

20 . The timed release pharmaceutical composition according to claim 17 , wherein the said composition is used to treat a patient suffering from mild, moderate or severe Alzheimer's disease.

21 . A timed release pharmaceutical composition comprising donepezil, wherein the composition exhibits the following in vitro dissolution profile when tested in a Paddle dissolution apparatus at 50 rpm in 900 ml 6.8 buffer at 37° C.

less than about 20% w/w of donepezil is released in 3-4 hrs, and

more than 85% w/w of donepezil is released after 12 hrs.

22 . The timed release pharmaceutical composition according to claim 21 , when administered orally provides reduced incidence of insomnia and nightmares.

23 . The timed release pharmaceutical composition according to claim 21 , when administered orally provides reduced incidence of sundowning syndrome.

24 . The timed release pharmaceutical composition according to claim 21 , wherein the said composition shortens the titration period required for donepezil administration.

25 . The timed release pharmaceutical composition according to claim 21 , wherein the said composition shortens the titration period required for donepezil administration by two to four weeks.

26 . The timed release pharmaceutical composition according to claim 21 , wherein the said composition is used to treat a patient suffering from a disease or a condition characterized by symptoms of dementia and/or cognitive impairments.

27 . The timed release pharmaceutical composition according to claim 21 , wherein the said composition is used to treat a patient suffering from mild, moderate or severe Alzheimer's disease.

28 . A timed release pharmaceutical composition comprising donepezil, wherein the single dose oral administration of the said composition provides dose corrected AUC (o-t) within about 80 to about 125% of the dose corrected AUC (o-t) of sustained release composition of donepezil, administered orally in a single dose.

29 . The timed release pharmaceutical composition according to claim 28 , wherein the said composition provides reduced incidence of insomnia and nightmares.

30 . The timed release pharmaceutical composition according to claim 28 , wherein the said composition shortens the titration period required for donepezil administration.

31 . The timed release pharmaceutical composition according to claim 28 , wherein the said composition shortens the titration period required for donepezil administration by two to four weeks.

32 . The timed release pharmaceutical composition according to claim 28 , wherein the said composition is used to treat a patient suffering from a disease or a condition characterized by symptoms of dementia and/or cognitive impairments.

33 . The timed release pharmaceutical composition according to claim 28 , wherein the said composition is used to treat a patient suffering from mild, moderate or severe Alzheimer's disease.

34 . A timed release pharmaceutical composition comprising donepezil, wherein the said composition provides a plasma donepezil concentration profile which simulates the Ach secretion in the brain endogenous acetylcholine plasma profile.

35 . The timed release pharmaceutical composition according to claim 34 , has a drug release profile such that the release is delayed by about 2 to about 8 hrs, wherein maximum plasma concentration of donepezil (Cmax) is attained about 8 to about 12 hours after administration.

36 . The timed release pharmaceutical composition according to claim 34 , wherein the said composition provides a reduced incidence of insomnia and nightmares.

37 . The timed release pharmaceutical composition according to claim 34 , wherein the said composition provides a reduced incidence of sundowning syndrome.

38 . The timed release pharmaceutical composition according to claim 34 , wherein the said composition shortens the titration period required for donepezil administration.

39 . The timed release pharmaceutical composition according to claim 34 , wherein the said composition shortens the titration period required for donepezil administration.

40 . The timed release pharmaceutical composition according to claim 34 , wherein the said composition is used to treat a patient suffering from a disease or a condition characterized by symptoms of dementia and/or cognitive impairments.

41 . The timed release pharmaceutical composition according to claim 34 , wherein the said composition is used to treat a patient suffering from mild, moderate or severe Alzheimer's disease.