Many drugs used for the treatment of common diseases are associated with various adverse effects and limited bioavailability. The suppression of such problems continues to be a very important target for scientists. The development of prodrugs for controlled release in vivo is an attractive way to overcome these problems. Classical in prodrug is an inactive molecule which the parent drug is covalently bonded to a carrier unit, and which can liberate the drug through chemical or enzymatic pathways. A new and interesting prodrug system for amine, alcohol, and thiol drugs takes advantage of several easy intramolecular cyclization reactions. So, the cyclization process can control the release rate of the parent drug. In this paper is a review about the prodrug strategies based on intramolecular cyclization reactions is presented.
Prodrugs; Intramolecular cyclization; Drugs
