In this paper we studied to obtain nano-sized particles by the rapid expansion of supercritical CO 2 in the aquatic environment (RESAS), obtained on a pilot installation of the upgraded Thar RESS-100-2 Base. The results of a particle size of nano ibuprofen and methyl paraben at a pressure of 8-20 MPa, the extraction temperature Tex = 293 to 333 K, the internal diameter of the nozzle 50, 65, 75 and 80 microns. The regularities of the influence of operating parameters and geometry of the nozzles on the average size of the particles.