Patent ID: 6906030

Claim:
A delivery composition comprising: (a) a peptide; and (b) at least one diketopiperazine having the formula: wherein R 1 and R 2 are C 1 -C 24 alkyl or C 1 -C 24 alkenyl and have at least one functional group selected from the group consisting of oxygen, amide, and carboxyl groups; both R 1 and R 2 , optionally, are substituted with C 1 -C 4 alkyl, C 1 -C 4 alkenyl, C 1 -C 4 alkoxy, —OH, —SH, and —CO 2 R 3 or any combination thereof; wherein R 3 is hydrogen, C 1 -C 4 alkyl, or C 1 -C 4 alkenyl; and R 1 and R 2 are interrupted by oxygen, nitrogen, sulfur, or any combination thereof.