Targeted Prodrugs

Abstract

Generally, prodrugs are obtained to overcome certain problems associated with their parent drugs. The old classical/ traditional prodrugs suffer from decreased bioavailability and a high profile of side effects due to activation at sites other than the desired site. Recently, they have been replaced by the new targeted prodrugs which have more therapeutic efficiency and less associated side effects. Targeted prodrugs are synthesized to deliver the desired drugs to a certain organ/cell in the body, thus, overcoming problems associated with traditional prodrugs. This type of prodrugs achieves its aim depending on the presence of unique cellular conditions at the desired target, especially the availability of certain enzymes and transporters at these target sites. In this chapter, the majority of the discussion is devoted to cover and address many methods for targeting different organs and cells. Some of these methods have proved their success while others are still under investigation. Due to an increase in the number of detected cancers and lack of effective treatments, targeting methodology was given a high priority and greatest devotion in this chapter. Several methods including active and passive targeting and many others are discussed in details. Targeting the central nervous system by studying the physiological nature of the blood brain barrier; taking advantage of the presence of certain transporters has been addressed. Another respected part of this chapter was devoted to colon targeting by the prodrug approach which covers some of prodrugs based on linkers that can be solely cleaved by the colonic microflora. This chapter documents in details the human immune deficiency virus and kidney targeting methods as well.