abstract |
A pharmaceutically acceptable salt of a heterocyclic compound according to Formula 1: ** Formula ** in which R1 or R2 comprise 4-X-aminobutyl and in which X is selected from the group consisting of succinyl, glutaryl, maleyl, citraconyl, malonyl, oxalyl and fumaryl; E1 and E2 are NH; and said salt further comprises at least one cation; and wherein said salt is not a lithium salt of 2,5-diaspartyl-3,6-diketopiperazine or 2,5-diglutamyl-3,6-diketopiperazine and said salt is in a solid form; wherein the heterocyclic compound comprises a diketopiperazine. |