A polyacrylamide-based copolymer reduces or prevents aggregation of biologic molecules including proteins, peptides, and nucleic acids, and lipid-based vehicles such as liposomes, lipid nanoparticles, polymerosomes, and micelles, in aqueous formulations at hydrophobic interfaces, thereby increasing the thermal stability of the molecules in the formulation. Methods and compositions comprising the copolymer and a protein or the copolymer and insulin can be used for treating conditions including diabetes.