Hydrophilic Coated Catheter Sterilization via Segmented Packaging

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Solution Overview

Problem

Radiation sterilization of hydrophilic coated catheters often reduces coating performance due to radical-induced changes, leading to decreased lubricity and extended activation times, which are not suitable for ready-to-use catheter assemblies.

Innovation Solution

A method involving a catheter package made of low moisture transmission material where the hydrophilic coating and wetting fluid are initially separated, allowing activation via gravity or inertia after radiation sterilization, ensuring the coating remains effective throughout the shelf life without user activation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If radiation sterilization is performed on activated hydrophilic coated catheters, then sterilization is achieved, but coating performance is reduced due to radical-induced changes

Engineering Contradiction:
Improvesterilization effectivenessVSAvoidcoating performance
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The catheter package is divided into a first cavity containing the catheter and a second cavity containing wetting liquid, separated by a gas permeable liquid impermeable barrier. This segmentation prevents contact between the wetting liquid and catheter during sterilization while allowing gas exchange, thus protecting the coating from radical damage during sterilization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The catheter is sterilized in an inactive state before activation. The packaging system is designed to maintain the catheter in a non-activated state during sterilization, then allows activation after sterilization is complete, ensuring the coating is not exposed to radicals during the critical sterilization phase.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If hydrophilic coating is activated before sterilization, then coating lubricity is improved, but activation time is extended to 6 weeks

Engineering Contradiction:
Improvecatheter lubricityVSAvoidactivation time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The packaging system is prepared in advance with separate compartments for the catheter and wetting liquid, allowing sterilization to proceed without activation. After sterilization, the system automatically allows activation to occur rapidly without requiring extended waiting periods.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The barrier material transitions from maintaining separation during sterilization to allowing liquid passage after sterilization. The gas permeable liquid impermeable barrier enables gas exchange during sterilization but allows wetting liquid to pass through after sterilization, enabling rapid activation.

Inventive Principle:
Principle #36Phase transitions

3Ease of operation

If wetting liquid is placed in direct contact with catheter in package, then activation is achieved, but spillage risk increases during handling

Engineering Contradiction:
Improveactivation readinessVSAvoidspillage risk
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The package is segmented into separate cavities for the catheter and wetting liquid, connected by a controlled barrier. This segmentation prevents free movement and spillage of wetting liquid while ensuring controlled activation through the gas permeable liquid impermeable barrier.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The gas permeable liquid impermeable barrier acts as an intermediary between the wetting liquid and catheter. It prevents direct contact and potential spillage during handling and sterilization, while still allowing gas exchange and controlled liquid passage after sterilization for activation.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 maintains the hydrophilic coating's lubricity and reduces activation time, providing a ready-to-use catheter assembly that is sterile and effective for immediate use while minimizing the risk of spillage and degradation.

Implementation Method 1

the liquid in the second cavity changes phase into vapor, the vapor passes the gas permeable barrier between the liquid and the hydrophilic coated catheter

Methodology Applied
Scientific EffectPhase change (liquid to vapor): Phase Change

Implementation Method 2

the vapor passes the gas permeable barrier between the liquid and the hydrophilic coated catheter

Methodology Applied
Scientific EffectPermeation: Permeation

Implementation Method 3

a hydrophilic coating on the catheter tube is activated prior to use by means of a wetting fluid

Methodology Applied
Scientific EffectHydrophilic absorption: Absorption (physical)

Implementation Method 4

bringing the wetting fluid into contact with at least the insertable length of the hydrophilic coating of the catheter and activating at least the insertable length of the hydrophilic coating of the catheter

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 5

A typical method used for sterilization of catheter assemblies is radiation sterilization

Methodology Applied
Scientific EffectRadiation sterilization: Radiation

Implementation Method 6

activating at least the insertable length of the hydrophilic coating of the catheter via gravity and / or inertia

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2845619B1Method for making a ready-to-use catheter assembly and ready-to-use catheter assembly
Publication Date: 2019.03.06 WILLY RUSCH GMBH
  • EP2845619B1 patent drawingFigure 1a~1e
  • EP2845619B1 patent drawingFigure 2
  • EP2845619B1 patent drawingFigure 3

AI summary

The present patent application refers to a method of making a ready-to-use catheter assembly (1, 1') and a ready-to-use catheter assembly made according to this method. It is an object of the present patent application to provide a ready-to-use catheter assembly which avoids any degradation of the catheter during sterilization. The method therefore comprises the following steps: Placing a catheter (3) with a hydrophilic coating and a wetting fluid (4) in a catheter package (2, 2') made of a material with low moisture transmission while the package is in a first condition wherein at least an insertable length of the hydrophilic coating of the catheter is not in contact with the wetting fluid, sterilizing the catheter package with the catheter and the wetting fluid by means of radiation sterilization while the catheter package is kept in a condition in which at least the insertable length of the hydrophilic coating of the catheter is not in contact with the wetting fluid, transferring the catheter package with the catheter and the wetting fluid into a second condition, thereby bringing the wetting fluid into contact with at least the insertable length of the hydrophilic coating of the catheter and activating at least the insertable length of the hydrophilic coating of the catheter via gravity and / or via inertia.