USE OF PURIFIED SURFACE MODIFIERS TO PREVENT PARTICLE AGGREGATION DURING STERILIZATION

This invention discloses a composition comprised of nanoparticles having a purified polymeric surfactant as a surface modifier adsorbed on the surface thereof and a cloud point modifier associated therewith, which cloud point modifier is present in an amount sufficient to increase the cloud point of the surface modifier. Preferred purified polymeric surfactants are purified polyalkyleneoxide substituted ethylenediamine surfactants. A preferred cloud point modifier is polyethylene glycol. This invention further discloses a method of making nanoparticles having a purified polymeric surfactant as a surface modifier adsorbed on the surface and a cloud point modifier associated therewith, comprised of contacting said nanoparticles with the cloud point modifier for a time and under conditions sufficient to increase the cloud point of the surface modifier.