There is not a good general procedure for concentration of liposomes. Large liposomal particles can be concentrated using centrifugation. The lowest speed possible to achieve pelleting is best since higher speeds could induce deformation and/or fusion of particles. Centrifugation is only possible with larger particles (>100nm). Small, sonicated (SUV) particles will not readily pellet due to their small size. Other methods of concentration may be possible but could lead to particle shape deformation depending on the sample and technique.