Described herein is a process for preparing nano-suspensions, wherein the process comprises: providing an admixture of at least one active pharmaceutical compound, an aqueous dispersion medium, and milling media and applying thereto acoustic energy having a frequency of from about 10 hertz to 1000 hertz and which supplies a linear acceleration of from about 10 G's to about 100 G's (where “G” is the force of gravity) for a period sufficient to supply a nano-suspension having a D50 of less than about 1 micron, preferably less than about 500 nm. Described also are nano-suspensions having novel properties prepared via the inventive process.