Polyvinyl chloride catheters with repressed migration of plasticizers

Impart flexibility and desired softness of polyvinylchloride (PVC) – one of the most widely used polymeric materials for medical device production – is achieved by addition of appropriate amount of plasticizer, usually di(2-ethylhexyl phthalate) (DEHP), into polymer matrix. DEHP is not chemically bonded to PVC and migrates to the surrounding media such as saliva, blood, plasma, or serum resulting in several toxic effects. Migration of DEHP can be significantly suppressed by embedding PVC into another polymer preventing its direct contact with surrounding liquid media. Coextruded TPU-PVC-TPU catheters were prepared with various thicknesses of TPU layers to evaluate its repressing effect on DEHP releasing. Releasing kinetic of DEPH from both three layered catheters and PVC catheters into the acetonitrile was observed in various time intervals and determined using reverse-phase liquid chromatographic technique