In accordance with the present invention, there are provided compositions and methods useful for the in vivo delivery of substantially water-insoluble pharmacologically active agents (such as the anticancer drug paclitaxel) in which the pharmacologically active agent is delivered in the form of suspended particles coated with protein (which acts as a stabilizing agent). In particular, protein and pharmacologically active agent in a biocompatible dispersing medium are subjected to high shear, in the absence of any conventional surfactants, and also in the absence of any polymeric core material for the particles. The use of specific composition and preparation conditions enables the reproducible production of unusually small nanoparticles of less than 200 nm diameter, which can be sterile-filtered.
