from the surface of the balloon to the artery wall during inflation of the balloon the amount of drug transferred is typically less than 25 of the total amount of drug available on the surface after inflation the balloon can be rewrapped and removed from the artery or redeployed elsewhere to another lesion site little drug is lost during removal process and the oil based formulations provide for a lubricious coating to the balloon without using polymers or hydrogels when used to coat metal coronary stents the oil based formulations permit uniform coating of the entire metal surface coating can be applied to both the stent and the delivery balloon at the same time unlike the balloon coated option that is removed from the artery immediately after deployment the coated stent remains in place and will slowly deliver the entire amount of drug to the artery wall the dissolution rate of the oil based hydrophobic drug system is compatible with sustained release delivery of the drug to the artery wall without a controlling polymer or hydrogel and wound healing potential as vitamin e 39 s antioxidant activity may augment the anti restenotic activity of the drug and enhance wound healing at the site where the stent struts are embedded in the artery wall the current formulation approach applied to an angioplasty balloon demonstrates rapid pressure transfer delivery of a sufficient amount of water insoluble materials to the artery wall using a non polymer hydrogel base consisting of oil capable of dispersing the drug the formulation approach works to keep a lipid material in a very deliverable form without further solid state changes that could lead to ineffective delivery the delivery.