The present invention relates to a method for producing polymer-encapsulated nanoparticles comprising the steps of: pumping supercritical fluid into a pressurised vessel, at a predetermined pressure spraying a solution comprising a compound to be encapsulated, a polymer and an organic solvent into the vessel collecting precipitated particles on a filter and washing the particles with the supercritical fluid to remove residual solvent characterised in that: the difference between the melting point of the polymer and the melting point of the compound to be encapsulated is not more than 10 °C.
