The elution of poly (vinyl alcohol) from a contact lens: The realization of a time release moisturizing agent/artificial tear

The use of a contact lens as a polymeric delivery vehicle is presented. Specifically, the elution of nonfunctionalized poly (vinyl alcohol) (PVA) from nelfilcon A hydrogel lenses is presented as a model of delivering polymeric active agents to the eye. High molecular weight nonfunctionalized PVA is added to the lens matrix for later release into the tears. This is made possible by photo crosslinking a macromer species in lieu of monomeric polymerization. Consistent near zero order release of 0.062% (wt/wt) was demonstrated in vitro over a 20-h period. The result is a new contact lens device based on the slow release of PVA. In vivo results demonstrate that this product improves the wearing comfort of this type of contact lens and acts as a model basis for drug delivery. (c) 2006 Wiley Periodicals, Inc.