Paclitaxel-Shellac Coated Catheter Balloons for Restenosis Prevention
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Solution Overview
Problem
Current methods for coating catheter balloons with paclitaxel are ineffective in preventing restenosis due to prolonged inflation times, leading to arterial injury and inadequate drug release, while drug-eluting stents cause late thrombosis and inhomogeneous drug distribution.
Innovation Solution
A coating method using a combination of paclitaxel and shellac on catheter balloons, where paclitaxel and shellac solutions are applied and dried to create a coating that allows for rapid and homogeneous drug release, even after short inflation times, enhancing tissue penetration and reducing restenosis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current paclitaxel coating methods are used on catheter balloons, then the coating can be applied, but the drug release is inadequate and restenosis prevention fails
Solution Approach 1:
The patent uses a composite coating formulation containing paclitaxel dispersed in shellac resin, combined with penetration enhancers (surfactants or organic solvents). This composite material system enables rapid and homogeneous drug release from the coating, achieving effective tissue concentrations while preventing restenosis, thereby resolving the contradiction between reliable restenosis prevention and efficient drug release.
Solution Approach 2:
The patent modifies the coating's drug release parameters by incorporating penetration enhancers that alter the coating's permeability and drug dissolution characteristics. This changes the release kinetics from slow and inadequate to rapid and homogeneous, achieving both reliable restenosis prevention and high drug release efficiency within the short balloon inflation time.
2Quantity of substance
If prolonged inflation time is used to achieve sufficient drug release, then more drug can be transferred to the vessel wall, but arterial injury increases
Solution Approach 1:
The patent enables the drug delivery process to be completed rapidly during the brief balloon inflation period (typically 30-60 seconds). The enhanced coating formulation allows sufficient paclitaxel transfer to occur within this short time window, skipping the need for prolonged inflation and thereby avoiding extended arterial injury while achieving adequate drug delivery.
Solution Approach 2:
The patent changes the drug release rate parameter by incorporating penetration enhancers in the coating formulation. This increases the drug transfer efficiency, allowing sufficient paclitaxel delivery during short inflation times, thus resolving the contradiction between achieving adequate drug quantity transfer and minimizing arterial injury from prolonged inflation.
3Duration of action of stationary object
If drug-eluting stents are used to provide sustained drug release, then late thrombosis risk increases and drug distribution becomes inhomogeneous
Solution Approach 1:
The patent extracts the drug delivery function from the stent structure itself, using a separate catheter balloon coating system instead. This separates the mechanical support function (stent) from the drug delivery function (coating), allowing rapid drug release during balloon inflation without the sustained release mechanism that causes late thrombosis in drug-eluting stents, thereby improving safety while maintaining effective drug delivery.
Solution Approach 2:
The patent uses periodic action by delivering the drug in a single rapid burst during balloon inflation, rather than sustained release over months. This periodic drug delivery approach achieves effective anti-proliferative action without the prolonged exposure that causes late thrombosis, resolving the contradiction between duration of action and safety.
4Object-affected harmful factors
If short inflation time is used for catheter balloon dilatation, then patient safety is improved, but drug release is insufficient
Solution Approach 1:
The patent changes the drug release rate parameter by incorporating penetration enhancers (surfactants or organic solvents) in the coating formulation. This increases the drug dissolution and transfer rate, allowing sufficient paclitaxel release during short inflation times (30-60 seconds), thereby resolving the contradiction between minimizing arterial injury from prolonged inflation and achieving adequate drug release.
Solution Approach 2:
The patent enables rapid drug release to occur during the brief balloon inflation period, rushing through the drug delivery process in alignment with the short inflation time. This achieves sufficient drug transfer without requiring prolonged inflation, resolving the contradiction between short inflation time for safety and adequate drug release quantity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The paclitaxel-shellac coating achieves up to 20-fold higher tissue concentrations of paclitaxel, effectively inhibiting smooth muscle cell proliferation and reducing neointimal hyperplasia, with improved safety and efficacy compared to traditional coatings, allowing for shorter inflation times and reduced arterial injury.
Implementation Method 1
a sufficient amount of pharmacological agent is transferred to the vessel wall to avoid re-constriction or reocclusion of the vessel due to the dilatation of the vessel and the delivery of active agents
Implementation Method 2
A coating method using a combination of paclitaxel and shellac on catheter balloons, where paclitaxel and shellac solutions are applied and dried to create a coating
Data Source
AI summary
The present invention relates to a method for coating catheter balloons with the pharmacological agent paclitaxel and the biological and biodegradable polymer composition shellac and optionally further components. Moreover the present invention relates to paclitaxel and shellac coated catheter balloons obtained according to the coating methods disclosed herein as well as the use of such coated catheter balloons for the short time release of the pharmaceutically active agent paclitaxel for prophylaxis and treatment of restenosis especially restenosis caused by angioplasty. The coated catheter balloons can be used alone or in combination with a coated or uncoated stent crimped on the catheter balloon before or after the coating with shellac and paclitaxel.