The process for manufacturing porous nanoparticles disclosed herein includes feeding a dry-blended mixture of at least one resin and a neutralizing agent into a feed section of a screw extruder, injecting a surfactant solution downstream of the hopper, and adding an aqueous composition both directly after the surfactant solution as well as further downstream. Porous nanoparticles having a particle size of from about 50 nm to about 2 μm and a pore diameter of from about 20 nm to about 400 nm may be continuously recovered from the extruder following this process.