A composition in the form of an injectable aqueous solution, for which the pH is comprised from 6.0 to 8.0, includes at least:a) amylin, an amylin receptor agonist or an amylin analogue；b) a co-polyamino acid bearing carboxylate charges and hydrophobic radicals Hy, said co-polyamino acid being constituted of glutamic or aspartic units and said hydrophobic radicals Hy chosen according to formula X as defined below:c)characterized in that the composition does not include basal insulin for which the isoelectric point IP is comprised from 5.8 to 8.5. The composition also includes a prandial insulin.
