Abstract: Process for the preparation of submicroscopic particles formed of a polymerized alkyl cyanoacrylate and containing a biologically active substance.At least one alkyl cyanoacrylate, in which the term "alkyl" denotes an alkyl radical having 1 to 12 carbon atoms, is added, with stirring, to pure water or to an aqueous solution or aqueous colloidal solution of an acid and/or of another water-soluble substance, and the stirring is continued until substantially all the alkyl cyanoacrylate has been converted to submicroscopic particles formed of polyalkyl cyanoacrylate; a biologically active substance is introduced into the reaction medium before the introduction of the monomer or after formation of the submicroscopic particles.The submicroscopic particles are useful as carriers for substances such as medical substances or products for diagnosis.

Abstract: The invention relates to new therapeutic agents against Leishmaniasis.These therapeutic agents consist of submicroscopic particles whose diameter is less than 500 nanometers, the particles being obtained by the micellar polymerization of an alkyl cyanoacrylate in which the alkyl chain contains from 1 to 12 carbon atoms.The therapeutic agents according to the invention may be administered parenterally.

Abstract: Biodegradable particles, with a diameter smaller than 500 nanometers, formed by the micellar polymerization of an alkyl-cyano-acrylate where the term "alkyl" means a lower alkyl radical having 1 to 4 carbon atoms and containing a biologically active substance. Also provided are processes for making pharmaceutical compositions containing the biodegradable particles and using the particles in pharmaceutical and diagnostic applications.