Nanosuspension of ibuprofen/polyvinyl alcohol composite functionalized by chitosan was fabricated by supercritical fluid extraction of emulsion (SFEE) in microfluidic segmented flow combined with chitosan dissolution technique using carbon dioxide. Ethyl acetate/water emulsion was prepared and ethyl acetate was extracted from the droplets dispersed in the emulsion into supercritical carbon dioxide on SFEE. The phase behavior during SFEE was observed with a view cell for the further understanding of the mass transfer during ethyl acetate removal from the emulsion. The controllability of particle size in the suspension was achieved by changing the amount of ibuprofen loaded in the emulsion. The fabricated particles of ibuprofen/polyvinyl alcohol with chitosan in the suspension were positively charged thus, bio-adhesive and the average size was 231.4 nm. The suspension can load ibuprofen 0.3 wt.%, which is 140 times larger amount than that in the saturated aqueous solution.