Claims for Patent: 8,133,514

Summary for Patent: 8,133,514

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; Samuel J. (Larchmont, NY)
Assignee:	MannKind Corporation (Valencia, CA)
Application Number:	12/473,192
Patent Claims:	1. A delivery composition comprising: (a) an active agent; and (b) at least one di-C-substituted diketopiperazine of formula I: ##STR00005## wherein R and R.sup.1 are each C.sub.2-C.sub.24 alkenyl and have at least one functional group selected from the group consisting of O and carboxyl group, and at least one of R and R.sup.1 contain a carboxyl group; and wherein R and R.sup.1 are optionally interrupted by O or N, or a 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. A delivery composition as defined in claim 1, wherein said active agent comprises a fragrance. 6. A delivery composition as defined in claim 1, wherein said active agent comprises a biologically active agent. 7. A delivery composition as defined in claim 6, wherein said biologically active agent is selected from the group consisting of a peptide, a mucopolysaccharide, a carbohydrate, a lipid, a pesticide, or any combination thereof. 8. The delivery composition as defined in claim 7, wherein said biologically-active agent 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, an antigen, a monoclonal antibody, somatostatin, adrenocorticotropin, gonadotropin releasing hormone, oxytocin, vasopressin, vancomycin, desferrioxamine (DFO), or any combination of any of the foregoing. 9. A delivery composition as defined in claim 6, wherein said biologically-active agent is selected from the group consisting of an interferon, interleukin-II, insulin, heparin, calcitonin, oxytocin, vasopressin, cromolyn sodium, vancomycin, DFO, or any combination of any of the foregoing. 10. A delivery composition as defined in claim 1, wherein said diketopiperazine is derived from two .alpha.-amino acids. 11. A delivery composition as defined in claim 10, wherein said two .alpha.-amino acids from which said diketopiperazine is derived are independently selected from the group consisting of glutamic acid, aspartic acid, tyrosine, phenylalanine, and optical isomers thereof. 12. A delivery composition as defined in claim 10, wherein said two .alpha.-amino acids from which said diketopiperazine is derived are the same. 13. A delivery composition as defined in claim 10, wherein said diketopiperazine is prepared by the thermal condensation of said two .alpha.-amino acids from which said diketopiperazine is derived. 14. A delivery composition as defined in claim 1, further comprising (c) at least one enzyme inhibitor. 15. 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. 16. A dosage unit form as defined in claim 15, comprising an oral dosage unit form. 17. A method for preparing microspheres containing an active agent, said method comprising: (A) solubilizing, in a solvent, at least one di-C-substituted diketopiperazine according to claim 1; and (B) contacting said diketopiperazine solution with said active agent and a precipitator solution in which said diketopiperazine is insoluble. 18. A method as defined in claim 17, 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.