Design, production and characterization of gelatin microspheres and disks as drug delivery system. Among natural polymers (preferred for their low toxicity and biocompatibility), gelatin represents a good raw material since it easily forms films and particles. In addition, gelatin is available in a pyrogen-free form and it can be used for the production of delivery systems requiring bioadhesion to mucosal tissues. In our laboratory we have developed advanced procedures for thermal hardening treatments or ‘natural’ cross-linking of gelatin microparticles by sugar or sugar-derived compounds.