The present invention relates to a system for administering active ingredients comprising nanoparticles having an average size of less than 1 micrometer in turn comprising: (a) at least one anionic polymer (b) a cationic cross-linking agent and optionally (c) a cationic polymer characterized in that the nanoparticles are cross-linked by means of electrostatic type interactions. Additionally, the invention relates to pharmaceutical, cosmetic, personal hygiene and nutritional compositions comprising said nanoparticle system, as well as to methods for the preparation and uses thereof.
