Hydrophilic Coating Radiation Stability via Thiosulfate Buffer

Solution Overview

Problem

Existing methods for sterilizing hydrophilic coatings with water-based wetting agents often result in degradation of lubricious properties and reduced dry-out time, especially when exposed to radiation, leading to instability and potential bacterial contamination during pre-use wetting.

Innovation Solution

Incorporating a thiosulfate anion and a buffer to maintain pH between 7 to 9 in the wetted hydrophilic coating, which helps stabilize the coating during radiation sterilization and extends the dry-out time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a hydrophilic coating is wetted with a water-based wetting agent prior to sterilization, then improved lubricity is achieved, but the coating deteriorates during radiation sterilization resulting in reduced dry-out time and loss of lubricious properties

Engineering Contradiction:

ImprovelubricityVSAvoidstability during sterilization

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent applies preliminary action by incorporating stabilizing agents (thiosulfate anion and buffer system) into the wetting agent before sterilization. This pre-treatment protects the hydrophilic coating from radiation-induced deterioration, maintaining both lubricity and dry-out time properties after sterilization. The stabilizing agents are added in advance to prevent rather than cure the deterioration that would otherwise occur during sterilization.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses thiosulfate anion and buffer system as intermediary substances that mediate between the water-based wetting agent and the radiation sterilization process. These intermediaries absorb or neutralize the harmful effects of radiation on the wetting agent, allowing the lubricious properties to be maintained throughout the sterilization process. The buffer system specifically mediates pH stability while thiosulfate provides radioprotection.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If a hydrophilic coating is pre-wetted and packaged for immediate use, then readiness for use is improved, but bacterial contamination risk increases during storage

Engineering Contradiction:

Improvereadiness for useVSAvoidbacterial contamination

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent incorporates a preservative into the wetting agent formulation, enabling the pre-wetted hydrophilic coating to maintain sterility during storage. This allows the product to be disposed of after single use with confidence that no bacterial contamination will occur. The preservative makes the wetting agent resistant to microbial growth, effectively creating a sterile, single-use product that combines the benefits of pre-wetting with safety.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If sterilization with radiation is applied to a wetted hydrophilic coating, then sterility is achieved, but the lubricious properties and dry-out time are degraded

Engineering Contradiction:

ImprovesterilityVSAvoiddry-out time

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent applies preliminary action by incorporating stabilizing agents (thiosulfate anion and buffer system) into the wetting agent before sterilization. This pre-treatment protects the hydrophilic coating from radiation-induced deterioration, maintaining both lubricity and dry-out time properties after sterilization. The stabilizing agents are added in advance to prevent rather than cure the deterioration that would otherwise occur during sterilization.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses thiosulfate anion and buffer system as intermediary substances that mediate between the water-based wetting agent and the radiation sterilization process. These intermediaries absorb or neutralize the harmful effects of radiation on the wetting agent, allowing the lubricious properties to be maintained throughout the sterilization process. The buffer system specifically mediates pH stability while thiosulfate provides radioprotection.

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

The solution significantly reduces deterioration of hydrophilic coatings during radiation sterilization, maintaining lubricious properties and stability, thus ensuring the hydrophilic coating's effectiveness and safety by preventing bacterial contamination.

Implementation Method 1

sterilization by radiation

Methodology Applied

Scientific EffectRadiation: Radiation

Implementation Method 2

a buffer for maintaining the pH at from 7 to 9

Methodology Applied

Scientific EffectpH buffering:

Implementation Method 3

a hydrophilic coating may absorb at least two times its weight of the wetting agent

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Implementation Method 4

Dry-out time is the amount of time that the wetted hydrophilic coating can retain suitable lubricious properties

Methodology Applied

Scientific EffectRetention:

Data Source

PatentEP3071250B1Reducing the deterioration of wetted hydrophilic coatings subjected to sterilization by radiation

Publication Date: 2019.06.05 DSM IP ASSETS BV

AI summary

A method of reducing the deterioration of a wetted hydrophilic coating caused by sterilization by radiation is provided. The method comprises the step of incorporating a thiosulfate anion and a buffer into the wetting hydrophilic coating comprising water. Some embodiments of the invention relate to a wetted hydrophilic coating, a wetting agent, a package comprising a wetted hydrophilic coating, and a method of sterilizing a wetted hydrophilic coating.