I am planning an in vivo where I need to inject drugs by intravenous (IV) injections into mice. I tried different solvents for the drugs and nothing seemed to work apart from this formulation: 1% DMSO, 40% PEG300, 5% Tween-80, and 54% Saline. I would like to know if anyone has tried to do IV injections using these solvents to make sure that they are not toxic to the mice. Any other suggestions/ insights are more than welcome!