Drug delivery composition comprising, based on the total weight of the composition: from 0.1 wt% to 99.9 wt% of a protein, and from 99.9 wt% to 0.1 wt% of a biodegradable polyesteramide copolymer comprising at least two different functional groups pendant to the polymer backbone, which functional groups are selected from the group of carboxyl, amine, hydroxyl, ester, amide, thiol or thioester groups whereby the polymer absorbs between 4-10% w/w water if exposed for 20 days to an aqueous medium at 37 °C, pH 7.2-7.4, and ion strength equivalent to 0.9 % NaCl solution in water, and wherein the polyesteramide copolymer is according to structural Formula: wherein m+p varies from 0.9-0.1 and q varies from 0.1 to 0.9; m+p+q=1 whereby m or p could be 0; n varies from 5 to 300 and wherein a is at least 0.1, b is at least 0.15 and a+b=1; wherein the m unit, p unit, a unit, and b unit are each randomly distributed throughout the polyesteramide copolymer; - R 1 is independently selected from the group consisting of (C 2 -C 20) alkyl; - R 3 and R 4 in a single backbone unit m or p, respectively, are independently selected from the group consisting of hydrogen, (C 1 -C 6)alkyl, (C 2 -C 6)alkenyl, (C 2 -C 6)alkynyl, (C 6 -C 10)aryl, (C 1 -C 6)alkyl, -(CH 2)SH, -(CH 2) 2 S 3,(CH 3) 2 -CH-CH 2 -, -CH(CH 3) 2, -CH(CH 3)-CH 2 -CH 3), -CH 2 -C 6 H 5, -(CH 2) 4 -NH 2, and mixtures thereof; - R 5 is independently selected from the group consisting of (C 2 -C 20)alkyl, (C 2 -C 20)alkylene; - R 6 is selected from bicyclic-fragments of 1,4:3,6-dianhydrohexitols of structural formula; - R 7 is independently selected from the group consisting of (C 6 -C 10) aryl (C 1 -C 6) alkyl or a protecting group - R 8 is -(CH 2) 4 -. from 0.1 wt% to 99.9 wt% of a protein, and from 99.9 wt% to 0.1 wt% of a biodegradable polyesteramide copolymer comprising at least two different functional groups pendant to the polymer backbone, which functional groups are selected from the group of carboxyl, amine, hydroxyl, ester, amide, thiol or thioester groups whereby the polymer absorbs between 4-10% w/w water if exposed for 20 days to an aqueous medium at 37 °C, pH 7.2-7.4, and ion strength equivalent to 0.9 % NaCl solution in water, and wherein the polyesteramide copolymer is according to structural Formula: wherein m+p varies from 0.9-0.1 and q varies from 0.1 to 0.9; m+p+q=1 whereby m or p could be 0; n varies from 5 to 300 and wherein a is at least 0.1, b is at least 0.15 and a+b=1; wherein the m unit, p unit, a unit, and b unit are each randomly distributed throughout the polyesteramide copolymer; - R 1 is independently selected from the group consisting of (C 2 -C 20) alkyl; - R 3 and R 4 in a single backbone unit m or p, respectively, are independently selected from the group consisting of hydrogen, (C 1 -C 6)alkyl, (C 2 -C 6)alkenyl, (C 2 -C 6)alkynyl, (C 6 -C 10)aryl, (C 1 -C 6)alkyl, -(CH 2)SH, -(CH 2) 2 S 3,(CH 3) 2 -CH-CH 2 -, -CH(CH 3) 2, -CH(CH 3)-CH 2 -CH 3), -CH 2 -C 6 H 5, -(CH 2) 4 -NH 2, and mixtures thereof; - R 5 is independently selected from the group consisting of (C 2 -C 20)alkyl, (C 2 -C 20)alkylene; - R 6 is selected from bicyclic-fragments of 1,4:3,6-dianhydrohexitols of structural formula; - R 7 is independently selected from the group consisting of (C 6 -C 10) aryl (C 1 -C 6) alkyl or a protecting group - R 8 is -(CH 2) 4 -. - R 1 is independently selected from the group consisting of (C 2 -C 20) alkyl; - R 3 and R 4 in a single backbone unit m or p, respectively, are independently selected from the group consisting of hydrogen, (C 1 -C 6)alkyl, (C 2 -C 6)alkenyl, (C 2 -C 6)alkynyl, (C 6 -C 10)aryl, (C 1 -C 6)alkyl, -(CH 2)SH, -(CH 2) 2 S 3,(CH 3) 2 -CH-CH 2 -, -CH(CH 3) 2, -CH(CH 3)-CH 2 -CH 3), -CH 2 -C 6 H 5, -(CH 2) 4 -NH 2, and mixtures thereof; - R 5 is independently selected from the group consisting of (C 2 -C 20)alkyl, (C 2 -C 20)alkylene; - R 6 is selected from bicyclic-fragments of 1,4:3,6-dianhydrohexitols of structural formula; - R 7 is independently selected from the group consisting of (C 6 -C 10) aryl (C 1 -C 6) alkyl or a protecting group - R 8 is -(CH 2) 4 -.