Avalon Laboratories uses several polyurethane-based and silicone/polyurethane-based materials for different applications of polymer solution casting. The company continues to work with several suppliers to test and incorporate radiopaque, lubricous and more biostable materials in this unique process. Polymer solution casting can provide seamless material transitions that offer varied property profiles along the shaft of a medical device. The process starts with solvent solubility testing, followed by testing of materials for mechanical properties, processing capabilities and biocompatibility and internal prototyping.
“We are seeing increased interest in the benefits of polymer solution casting for thin-walled catheter applications using micro coils and hypotubes,” said Huffer. “Hypotubes allow the catheter stiffness profile to be dictated by the hypotube cut pattern, which can be varied along the entire length and allows for very different characteristics from the distal to proximal end. In some instances, removing the need for multiple durometer materials often simplifies to one liner material and one jacket material. Thin walls are also achievable with micro coils, but tend to require multiple durometer materials to achieve the desired stiffness profile.”