Mechanisms of drug loading and release kinetics

In an effort to overcome the limitations of local drug delivery associated with the use of catheters, drug-loaded stents have been developed. Loading of such stents is achieved through either drug absorption (incorporation into a matrix) or drug adsorption (surface layering). The type of drug binding determines the elution profile/release kinetics of the drug, while the therapeutic target determines both the choice of drug used and the manner in which it is bound, i.e. eluting or non-eluting. While non-eluting stents have clinically reduced thrombotic complications following stent implantation, current experimental work concentrates on the use of eluting stents to combat restenosis.