Claims for Patent: 5,910,319

Summary for Patent: 5,910,319

Title:	Fluoxetine enteric pellets and methods for their preparation and use
Abstract:	A superior enteric formulation of the antidepressant drug, fluoxetine, is in the form of enteric pellets of which the enteric layer comprises hydroxypropylmethylcellulose acetate succinate.
Inventor(s):	Anderson; Neil R. (West Lafayette, IN), Harrison; Roger G. (Zionsville, IN), Lynch; Daniel F. (Indanapolis, IN), Oren; Peter L. (Fishers, IN)
Assignee:	Eli Lilly and Company (Indianapolis, IN)
Application Number:	08/867,196
Patent Claims:	1. An enteric fluoxetine pellet comprising a) a core consisting of fluoxetine and one or more pharmaceutically acceptable excipients; b) an optional separating layer comprising a non-reducing sugar and one or more pharmaceutically acceptable excipients; c) an enteric layer comprising hydroxypropylmethylcellulose acetate succinate (HPMCAS) and one or more pharmaceutically acceptable excipients; d) an optional finishing layer. 2. A pellet of claim 1 wherein the HPMCAS is partially neutralized with ammonium ions to the degree that from about 0% to about 25% of the succinic acid groups are neutralized. 3. A pellet of claim 2 wherein the HPMCAS is partially neutralized to the degree that from about 0% to about 15% of the succinic acid groups are neutralized. 4. A pellet of claim 1 wherein the separating layer is present. 5. A pellet of claim 1 wherein the average particle size of the fluoxetine is about 50 .mu.m or less. 6. A pellet of claim 5 wherein the core comprises an inert core on which the fluoxetine is deposited as a layer comprising in addition a pharmaceutically acceptable excipient. 7. A pellet of claim 6 wherein the separating layer is present. 8. A pellet of claim 7 wherein the HPMCAS is partially neutralized with ammonium ions to the degree that from about 0% to about 25% of the succinic acid groups are neutralized. 9. A pellet of claim 4 wherein the separating layer comprises a pharmaceutically acceptable sugar. 10. A pellet of claim 9 wherein the sugar is sucrose. 11. A process for preparing an enteric fluoxetine pellet comprising a) providing a core consisting of fluoxetine and one or more pharmaceutically acceptable excipients; b) optionally, applying to the core a separating layer comprising a non-reducing sugar and one or more pharmaceutically acceptable excipients; c) applying an enteric layer comprising HPMCAS and one or more pharmaceutically acceptable excipients, wherein the HPMCAS is supplied as an aqueous solution or suspension and the application takes place in an apparatus of the fluid bed type; d) optionally, applying a finishing layer. 12. A process of claim 11 wherein the HPMCAS is fully or partially neutralized with ammonium ions. 13. A process of claim 12 wherein the HPMCAS is neutralized to the degree that from about 25% to about 100% of the succinic acid groups are neutralized. 14. A process of claim 11 wherein the separating layer is applied. 15. A process of claim 14 wherein the separating layer comprises a pharmaceutically acceptable sugar. 16. A process of claim 15 wherein the sugar is sucrose. 17. A process of claim 11 wherein the core is prepared by applying fluoxetine and one or more pharmaceutically acceptable excipients to an inert core. 18. A process of claim 17 wherein the separating layer is applied and comprises a pharmaceutically acceptable sugar. 19. A formulation of claim 1 containing 20-100 mg base equivalent of fluoxetine. 20. A formulation of claim 1 containing about 80-90 mg base equivalent of fluoxetine. 21. A formulation of claim 1 containing about 90 mg base equivalent of fluoxetine. 22. A formulation of claim 19 wherein the fluoxetine is present as fluoxetine hydrochloride. 23. A formulation of claim 20 wherein the fluoxetine is present as fluoxetine hydrochloride. 24. A formulation of claim 21 wherein the fluoxetine is present as fluoxetine hydrochloride. 25. A gelatin capsule containing the formulation of claim 1. 26. A gelatin capsule containing the formulation of claim 24. 27. A formulation of claim 1 containing the following: 28. A gelatin capsule containing the formulation of claim 24. 29. A formulation according to claim 1 wherein the formulation additionally contains pindolol. 30. A method of treating people suffering from depression, obsessive-compulsive disorder, bulimia, pain, obsessive-compulsive personality disorder, post-traumatic stress disorder, hypertension, atherosclerosis, anxiety, anorexia nervosa, panic, social phobia, stuttering, sleep disorders, chronic fatigue, Alzheimer's disease, alcohol abuse, appetite disorders, weight loss, agoraphobia, improving memory, amnesia, smoking cessation, nicotine withdrawal symptoms, disturbances of mood and/or appetite associated with pre-menstrual syndrome, depressed mood and/or carbohydrate craving associated with pre-menstrual syndrome, disturbances of mood, disturbances of appetite or disturbances which contribute to recidivism associated with nicotine withdrawal, circadian rhythm disorder, borderline personality disorder, hypochondriasis, pre-menstrual syndrome (PMS), late luteal phase dysphoric disorder, pre-menstrual dysphoric disorder, trichotillomania, symptoms following discontinuation of other antidepressants, aggressive/intermittent explosive disorder, compulsive gambling, compulsive spending, compulsive sex, psychoactive substance use disorder, sexual disorder, schizophrenia, premature ejaculation, or psychiatric symptoms selected from stress, worry, anger, rejection sensitivity, and lack of physical energy comprising administering a formulation of claim 1. 31. A method of claim 30 employing a formulation containing 20-100 mg base equivalent of fluoxetine. 32. A method of claim 30 employing a formulation containing about 90 mg base equivalent of fluoxetine. 33. A method of claim 30 wherein the fluoxetine is present as fluoxetine hydrochloride. 34. A method of claim 31 wherein the fluoxetine is present as fluoxetine hydrochloride. 35. A method of claim 32 wherein the fluoxetine is present as fluoxetine hydrochloride. 36. A method of claim 30 employing a formulation containing the following: 37. A method of claim 30 of treating people suffering from pain, further comprising the coadministration of morphine, codeine or dextropropoxyphene. 38. A method of claim 37 employing a formulation containing 20-100 mg base equivalent of fluoxetine. 39. A method of claim 37 employing a formulation containing about 90 mg base equivalent of fluoxetine.