The study of these systems is of great interest as they give specificity to the action and reduce secondary effects to a minimum. In this sense, the group has studied formulations for the administration of cyclosporin A, insulin, NSAIDs, etc., through their chemical association to liposomes and microspheres. With the latter, it is also the intention to formulate mucoadhesive tablets for local administration of lidocaine and use them as an alternative to anaesthesia in dentistry.