Balloon Coating Rotation for Uniform Drug Morphology Control

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Solution Overview

Problem

Existing balloon coating methods fail to consistently control the morphological form of drugs on the balloon surface, affecting drug release and tissue transferability, as they lack the ability to selectively apply the proper quantity and set the desired morphological form of the drug coating.

Innovation Solution

A balloon coating method and device that uses a drive shaft fitted to the balloon catheter's hub to rotate the balloon while applying a coating solution, allowing for precise control of the drug's morphological form by maintaining a stable position and applying a predetermined pulling force to correct the balloon's curvature, ensuring a proper contact force and uniform coating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the balloon is rotated while applying coating solution, then the drug coating is formed on the balloon surface, but the morphological form of the drug cannot be consistently controlled

Engineering Contradiction:
Improvecontrol of drug morphological formVSAvoidconsistency of drug coating
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The balloon is pre-inflated to a predetermined volume before coating application, establishing a stable spherical shape that ensures consistent drug morphological form during the coating process. This preliminary inflation action prevents shape variations that would otherwise cause inconsistent coating results.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention controls the inflation pressure and volume of the balloon as key parameters to maintain a stable spherical shape during coating. By precisely controlling these physical parameters, the morphological form of the drug coating is consistently controlled across different batches and applications.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the coating solution is applied to the rotating balloon, then the drug is transferred to the balloon surface, but the quantity and uniformity of coating cannot be precisely controlled

Engineering Contradiction:
Improveuniformity of drug coatingVSAvoidquantity of coating solution
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The system monitors the coating application process and adjusts the coating solution flow rate and balloon rotation speed based on feedback from sensors that detect coating uniformity and quantity. This closed-loop control ensures precise control of both the quantity applied and the uniformity of the drug coating.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The balloon is rotated at a controlled speed during coating application, creating dynamic conditions that promote uniform distribution of the coating solution across the entire balloon surface. The rotation ensures that no single area receives excessive or insufficient coating, achieving precise uniformity control.

Inventive Principle:
Principle #15Dynamics

3Ease of manufacture

If the balloon is held stationary during coating, then the coating application is simple, but the drug morphological form cannot be properly set

Engineering Contradiction:
Improvesimplicity of coating processVSAvoiddrug morphological form control
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The balloon is rotated at a controlled speed during coating application, creating dynamic conditions that promote uniform distribution of the coating solution and proper drug crystallization. This rotation is essential for achieving the desired morphological form while maintaining a relatively simple coating process.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The periodic rotation of the balloon during coating application creates repeated cycles of coating solution application and drying across different surface areas. This periodic action ensures uniform drug morphological form development while keeping the overall process simple and efficient.

Inventive Principle:
Principle #19Periodic action

4Productivity

If the balloon curvature is not corrected, then the coating process is faster, but the contact force between dispensing tube and balloon is inconsistent

Engineering Contradiction:
Improvecoating speedVSAvoidcontact force consistency
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The balloon is pre-inflated to a predetermined volume and shape before the coating process begins, establishing a consistent spherical geometry that ensures uniform contact force between the dispensing tube and balloon surface throughout the coating application, maintaining both speed and precision.

Inventive Principle:
Principle #10Preliminary action

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

This method enables the precise application of a drug coating with a controlled morphological form, enhancing drug release and tissue transferability by maintaining a stable balloon position during rotation and applying a consistent contact force, thereby improving the effectiveness of the drug elution process.

Implementation Method 1

fitting a drive shaft for rotating the balloon catheter to a proximal portion of a hub of the balloon catheter

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

applying a coating solution containing the drug to the outer surface of the balloon

Methodology Applied
Scientific EffectDeposition: Deposition (physical)

Data Source

PatentEP3287166B1Balloon coating method, balloon rotation method, and balloon coating device
Publication Date: 2024.04.24 TERUMO KK
  • EP3287166B1 patent drawingFigure 1
  • EP3287166B1 patent drawingFigure 2
  • EP3287166B1 patent drawingFigure 3

AI summary

There are provided a balloon coating method, a balloon rotating method, and a balloon coating device, which can properly apply a coating solution to an outer surface of a balloon, and which can properly set a morphological form of a drug used in coating the balloon. There is provided a balloon coating method for forming a coating layer (32) containing a water-insoluble drug on an outer surface of a balloon (30) of a balloon catheter (10). The method has a step of fitting a drive shaft (111) for rotating the balloon catheter (10) to an opening portion of a three-way stopcock (170) to be attached to a proximal portion of a hub (40) to fix the drive shaft (111) by using a frictional force, and a step of moving a dispensing tube (134) for supplying a coating solution containing the drug in an axial direction of the balloon (30) while causing the drive shaft (111) to rotate the balloon (30) around an axis (X) of the balloon (30), so as to apply the coating solution to the outer surface of the balloon (30).