This course aims at furnishing general knowledge and issues related to the various stages of drug research and development, as well as the molecular bases for a better comprehension of the mechanisms of action of the drugs in the organism. The course also intends to provide basic knowledge on the design, synthesis, chemical-physical and toxicological properties, and utilization of some classes of drugs. A particular attention will be devoted to the comprehension of the mechanisms of action of the drugs at the molecular level, and of the relationships between their chemical structure and biological activity, in order to provide the student with the basics for an appropriate and rational drug design.