(240a) The Effect of Cosolvents on the Loading Efficiency and Release Profile of Anti-CD47 in the Emulsion Solvent Evaporation Technique

Side effects associated with the utilization of antibodies as therapeutics limit their systemic administration at high concentrations often needed for therapeutic impact. Thus, therapeutic antibodies are often considered for targeted delivery through their encapsulation within polymeric nanocarriers. The loading efficiency of antibodies via emulsion-based nanofabrication methods is normally very low. Thus, the fabrication techniques need to be modified to maximize the loading efficiency of antibodies. In this work, we utilized various cosolvents to improve the loading efficiency of anti-CD47, a therapeutic antibody used to block the marker of self signal for initiation of phagocytosis and destruction of atherosclerotic plaques and cancer lesions, via emulsion solvent evaporation technique. Our results demonstrate that a minimum amount of a cosolvent with minimal hydrophilicity can stabilize the antibody in the oil phase; thus, significantly improving the loading efficiency and prolonging the release profile of the antibody. Amongst the cosolvents screened, ethyl acetate was found to be the optimum choice and improved the loading efficiency of anti-CD47 in PLGA nanoparticles to 90% or higher.