Hi. my question is about the stability of polymeric micelle for a long period of time after storing at 4̊ C. I synthesis new PEGylated compound that could formation micelle structure in water environment but the stability of my micelles when I loading the hydrophobic drugs by solvent evaporation method in their hydrophobic core are very less and after a period of time, these structures were unstable. Why does this happen to occur? And if I using some perspective or antibacterial compound could achieve stable micelles ?