Claims for Patent: 7,829,120

Summary for Patent: 7,829,120

Title:	Trazodone composition for once a day administration
Abstract:	The invention relates to a once a day formulation of trazodone or a trazodone derivative. The formulation contains trazodone or a trazodone derivative and a controlled release excipient so that, once administered orally, the trazodone or the trazodone derivative is maintained at a therapeutic plasma concentration from at least 1 hour to at least 24 hours after initial administration. After administration, the initial therapeutic action takes effect within the first hour and lasts at least about 24 hours. This therapeutic effect remains relatively and substantially stable for the remaining period of 24 hours. The formulations can be used for treating depression and/or sleeping disorders.
Inventor(s):	Gervais; Sonia (Laval, CA), Smith; Damon (Saint-Laurent, CA), Rahmouni; Miloud (Pierrefonds, CA), Contamin; Pauline (Magny En Vexin, FR), Ouzerourou; Rachid (Anjou, CA), Ma; My Linh (Saint-Laurent, CA), Ferrada; Angela (Montreal, CA), Soulhi; Fouzia (Dollard-des-Ormeaux, CA)
Assignee:	Labopharm Inc. (Quebec, CA) Labopharm Europe Limited (Dublin, IE) Labopharm (Barbados) Limited (St. Michael, BB)
Application Number:	11/519,194
Patent Claims:	1. A sustained release pharmaceutical composition for once a day oral administration comprising about 20% to about 50% by weight of trazodone or a derivative thereof, about 20% to about 50% by weight of cross-linked high amylose starch, about 10% to about 25% by weight of hydroxypropylmethylcellulose, about 0% to about 5% by weight of cetylpyridinium chloride, about 0% to about 20% by weight of alginic acid, about 1% to about 5% by weight of sodium stearyl fumarate, and up to about 1% by weight of colloidal silicon dioxide, wherein the composition, when administered orally to a mammal, releases the trazodone or the derivative thereof so as to maintain a substantially constant effective plasma concentration between about 50 ng/mL and about 3000 ng/mL from at least about one hour to at least about 24 hours after initial administration. 2. The sustained release pharmaceutical composition according to claim 1, wherein the plasma concentration is effective at treating depression in the mammal. 3. The sustained release pharmaceutical composition according to claim 1, wherein the plasma concentration is effective at treating a sleep disorder in the mammal. 4. The sustained release pharmaceutical composition according to claim 1, wherein the composition comprises 150 mg of trazodone hydrochloride. 5. The sustained release pharmaceutical composition according to claim 4, wherein the plasma trazodone concentration achieved one hour after ingestion is between about 150 ng/mL and about 500 ng/mL. 6. The sustained release pharmaceutical composition according to claim 1, wherein the composition comprises 300 mg of trazodone hydrochloride. 7. The sustained release pharmaceutical composition according to claim 6, wherein the plasma trazodone concentration one hour after ingestion is between about 300 ng/mL and about 1000 ng/mL. 8. The sustained release pharmaceutical composition according to claim 1, wherein the composition comprises from about 35% to 50% by weight percent trazodone hydrochloride. 9. The sustained release pharmaceutical composition according to claim 1, wherein the cross-linked high amylose starch comprises between about 65% and 75% by weight amylose and is cross-linked with phosphorus oxychloride. 10. The sustained release pharmaceutical composition according to claim 9, wherein the cross-linked high amylose starch comprises hydroxypropyl side chains. 11. The sustained release pharmaceutical composition according to claim 10, wherein the cross-linked high amylose starch is gelatinized. 12. The sustained release pharmaceutical composition according to claim 1, wherein the mammal is a human. 13. The sustained release pharmaceutical composition according to claim 1, wherein the composition is in the form of a tablet. 14. The sustained release pharmaceutical composition according to claim 13, wherein the tablet is shaped in the form of a caplet. 15. The sustained release pharmaceutical composition according to claim 14, wherein the caplet comprises about 300 mg trazodone. 16. The sustained release pharmaceutical composition according to claim 1, which is adapted for administration before bedtime. 17. The sustained release pharmaceutical composition according to claim 16, wherein the composition provides substantially no drowsiness in a person about 8 hours after oral administration relative to repeated administrations of an immediate release trazodone composition. 18. A method of treating a sleeping disorder comprising administering to a person with the sleeping disorder a sustained release pharmaceutical composition of claim 1. 19. The method according to claim 18, wherein the disorder is treated to improve sleep architecture. 20. The method according to claim 19, wherein the composition is administered before bedtime. 21. A method of treating depression comprising administering once a day to a person with depression a sustained release pharmaceutical composition according to claim 1. 22. The method according to claim 21, wherein the composition is administered before bedtime. 23. The sustained release formulation according to claim 1, wherein the trazodone derivative is trazodone hydrochloride.