The therapeutic liquid and solid colloidal systems considered here are oil-in-water and water-in-oil microemulsions, polyalkylcyanoacrylate nanocapsules and solid lipid nanospheres. For each of the following are reported: chemico-physical behaviour in different media, amounts of drugs incorporated of different lipophilicities, release kinetics of the englobed drugs from the colloidal systems, often of the pseudo-zero order together with some “in vivo” results. Colloidal therapeutic systems can be proposed for various administration routes.