Claims for Patent: 6,663,898

Summary for Patent: 6,663,898

Title:	Carbon-substituted diketopiperazine delivery systems
Abstract:	Compositions useful in the delivery of active agents are provided. These delivery compositions include (a) an active agent; and (b) a carrier of at least one mono-C-substituted or di-C-substituted diketopiperazine. Methods for preparing these compositions and administering these compositions are also provided.
Inventor(s):	Milstein; Sam J. (Larchmont, NY)
Assignee:	Emisphere Technologies, Inc. (Tarrytown, NY)
Application Number:	10/125,836
Patent Claims:	1. A delivery composition comprising: (a) a peptide; and (b) at least one diketopiperazine having the formula: ##STR5## wherein R.sup.1 and R.sup.2 are C.sub.1 -C.sub.24 alkyl or C.sub.1 -C.sub.24 alkenyl and have at least one functional group selected from the group consisting of oxygen and amide groups; both R.sup.1 and R.sup.2, optionally, are substituted with C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkenyl, C.sub.1 -C.sub.4 alkoxy, --OH, --SH, and --CO.sub.2 R.sup.3 or any combination thereof; wherein R.sup.3 is hydrogen, C.sub.1 -C.sub.4 alkyl, or C.sub.1 -C.sub.4 alkenyl; R.sup.1 and R.sup.2 are interrupted by oxygen, nitrogen, sulfur, or any combination thereof. 2. A delivery composition as defined in claim 1, comprising a microsphere. 3. A delivery composition as defined in claim 2, wherein said microsphere comprises a microcapsule. 4. A delivery composition as defined in claim 2, wherein said microsphere has a diameter of less than about 10 .mu.m. 5. The delivery composition as defined in claim 1, wherein said peptide is selected from the group consisting of human growth hormone, bovine growth hormone, growth hormone-releasing hormone, an interferon, interleukin-II, insulin, heparin, calcitonin, erythropoietin, atrial naturetic factor, a monoclonal antibody, somatostatin, adrenocorticotropin, gonadotropin releasing hormone, oxytocin, vasopressin, vancomycin, or any combination of any of the foregoing. 6. A delivery composition as defined in claim 5, wherein said peptide is selected from the group consisting of an interferon, interleukin-II, insulin, heparin, calcitonin, oxytocin, vasopressin, vancomycin, or any combination of any of the foregoing. 7. A delivery composition as defined in claim 1, wherein said diketopiperazine is derived from two .alpha.-amino acids. 8. A delivery composition as defined in claim 7, wherein said two .alpha.-amino acids from which said diketopiperazine is derived are the same. 9. A delivery composition as defined in claim 7, wherein said diketopiperazine is prepared by the thermal condensation of said two .alpha.-amino acids from which said diketopiperazine is derived. 10. A delivery composition as defined in claim 1, further comprising (c) at least one enzyme inhibitor. 11. A pharmacological composition comprising: (a) at least one peptide; and (b) at least one diketopiperazine having the formula: ##STR6## wherein R.sup.1 and R.sup.2 are C.sub.1 -C.sub.24 alkyl or C.sub.1 -C.sub.24 alkenyl and have at least one functional group selected from the group consisting of oxygen and amide groups; both R.sup.1 and R.sup.2, optionally, are substituted with C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkenyl, C.sub.1 -C.sub.4 alkoxy, --OH, --SH, and --CO.sub.2 R.sup.3 or any combination thereof; wherein R.sup.3 is hydrogen, C.sub.1 -C.sub.4 alkyl, or C.sub.1 -C.sub.4 alkenyl; R.sup.1 and R.sup.2 are interrupted by oxygen, nitrogen, sulfur, or any combination thereof. 12. A dosage unit form comprising: (A) a delivery composition as defined in claim 1; and (B)(a) an excipient, (b) a diluent, (c) a disintegrant, (d) a lubricant, (e) a plasticizer, (f) a colorant, (g) a dosing vehicle, or (h) any combination thereof. 13. A dosage unit form as defined in claim 11, comprising an oral dosage unit form. 14. A method for administering a peptide to an animal in need thereof, said method comprising administering orally to said animal, a composition as defined in claim 1. 15. A method for preparing microspheres containing an active agent, said method comprising: (A) solubilizing, in a solvent, at least one diketopiperazine having the formula: ##STR7## wherein R.sup.1 and R.sup.2 are C.sub.1 -C.sub.24 alkyl or C.sub.1 -C.sub.24 alkenyl and have at least one functional group selected from the group consisting of oxygen and amide groups; both R.sup.1 and R.sup.2, optionally, are substituted with C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkenyl, C.sub.1 -C.sub.4 alkoxy, --OH, --SH, and --CO.sub.2 R.sup.3 or any combination thereof; wherein R.sup.3 is hydrogen, C.sub.1 -C.sub.4 alkyl, or C.sub.1 -C.sub.4 alkenyl; R.sup.1 and R.sup.2 are interrupted by oxygen, nitrogen, sulfur, or any combination thereof, to yield a diketopiperazine solution; and (B) contacting said diketopiperazine solution with said a peptide and a precipitator solution in which said diketopiperazine is insoluble. 16. A method as defined in claim 15, wherein said diketopiperazine solution has a pH within a first range and said precipitator solution has a pH within a second range, said first range being different than said second range. 17. A delivery composition as defined in claim 1, wherein R.sup.1 and R.sup.2 are interrupted by nitrogen. 18. A delivery composition as defined in claim 17, wherein R.sup.1 and R.sup.2 are substituted with --CO.sub.2 R.sup.3. 19. A delivery composition as defined in claim 18, wherein R.sup.3 is hydrogen. 20. A delivery composition as defined in claim 17, wherein the functional group is oxygen. 21. A delivery composition as defined in claim 17, wherein the functional group is an amide group. 22. A delivery composition as defined in claim 1, wherein R.sup.1 and R.sup.2 comprise an amide group. 23. A delivery composition as defined in claim 1, wherein the peptide is insulin. 24. A delivery composition as defined in claim 1, wherein the peptide is calcitonin. 25. A delivery composition as defined in claim 1, wherein the delivery composition is a solution comprising from about 10 to about 2000 mg of the diketopiperazine per ml of solution. 26. The delivery composition of claim 25, wherein the solution comprises from about 75 to about 500 mg of the diketopiperazine per ml of solution.