The present invention relates to a pharmaceutical composition comprising: a unimolecular multi-arm block copolymer having the structure: A(-0-B-L1-C)m-(L2-D-E)n wherein: A is a central core molecule comprising a residue of a polyol, O is oxygen, B is a hydrophilic oligomer, C is a polypeptide segment, D is a hydrophilic polymer segment, E is a capping group or a functional group, L1 and L2 are linkages, (m) is 3 to about 25, (n) is 2 to about 25, and (n) < (m) and a biologically active agent entrapped within the inner region of the unimolecular multi-arm block copolymer.
