Organic drug nanoparticles may be stabilized in nanosupensions by Rapid Expansion of Supercritical Solutions into Aqueous Solutions (RESSAS) using surfactant solutions. A model bubble column was used in the present work in order to study the influence of relevant system parameters, such as foam height and pH value, on the deposition and stabilization efficiency. It turned out that, already at low heights, the combination of deposition processes in the rising bubbles and in the foam results in high separation efficiency for nanoparticles, which are well stabilized by the surfactants. The pH value influences the foam properties and consequently the separation efficiency.