The invention provides a method for reducing the average size of biologically active compound particles or agglomerates suspended in a fluid by flowing one or more times said fluid having biologically active compound particles or agglomerates suspended therein through one or more magnetic fields to reduce the average size of a substantial portion of the biologically active compound particles or agglomerates by at least 25%. This method may be incorporated into a process for manufacturing a 10 biologically active compound formulation.