Methods and results
The polyisoprene tubes contain reservoirs which close when the balloon is relaxed and open when the balloon is expanded. Using paclitaxel+excipients as a model drug, the loading of the WOMBAT® IIb revealed that about 40% up to 70% of the drug is located in the reservoirs. Removal of the remaining part on the surface (not in the reservoirs) was done either mechanically by multiple sheath passages or by washing the (relaxed) balloons with ethanol-water mixtures. The efficiency to remove the drug from the surface and not from the reservoirs was tested by microscopic inspection and drug quantitation. Drug vessel uptake studies of WOMBAT® IIb (porcine model) revealed that the drug transfer from the reservoirs has a comparable efficacy as that of non-laser-structured polyisoprene-wrapped balloons. Hence, WOMBAT® IIb allows a safe and efficient drug transfer with minimal surface coating.
WOMBAT® is a trademark of AVIDAL Vascular GmbH, Germany, describing a new class of interventional products for intraluminal drug application: W raps over M edical BA lloons T echnology.
