Various embodiments of a system and process for reducing the size of solid particles are disclosed. In one embodiment the system includes a cavitation processor and a comminution processor in physical communication with one another to reduce the size of solid particles. In another embodiment, a process for reducing the size of solid particles includes passing the solid particles sequentially through a cavitation processor and a comminution processor which are in physical communication with one another. Examples of solid particles which may be used in the system and process herein, include pharmaceuticals, foods, inks and paints.