Provided herein is a composition comprising (a) nanoparticles comprising a poorly water soluble pharmaceutical agent and albumin, and (b) an edetate and citrate, wherein significant microbial growth is inhibited in the composition. Also provided is the composition of the invention for use in a method for the treatment of cancer in an individual. Further provided is a method of preserving a composition comprising nanoparticles comprising a poorly water soluble pharmaceutical agent and albumin against significant microbial growth comprising adding to the composition an edetate and citrate in an amount that is effective to inhibit significant microbial growth in the composition.
