Responsive polymers in controlled drug delivery

This article reviews the state-of-the art in responsive polymer systems for controlled drug delivery applications. The paper describes different types of stimuli-sensitive systems and gives an account of their synthesis through methods such as group transfer polymerization, atom transfer radical polymerization and reversible addition-fragmentation chain transfer polymerization. The article also discusses classification of various drug delivery systems: diffusion controlled systems, chemically controlled systems, swelling-controlled systems and modulated release systems. A survey of the recent literature on various stimuli-responsive polymer hydrogels in controlled drug delivery is also included. (C) 2008 Elsevier Ltd. All rights reserved.