Slidable Coating Layer for Prefilled Syringe Gaskets

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Solution Overview

Problem

Prefilled syringes face challenges in maintaining stable sliding performance and liquid-tightness over time, especially when using lubricants like silicone oil, which can interact with medical agent solutions, leading to degradation, and the use of organic tin compounds as catalysts raises environmental and health concerns.

Innovation Solution

A medical appliance with a slidable coating layer formed from a silicone-based resin produced by an addition reaction between silicone with vinyl groups and silicone with hydrogen groups, eliminating the need for organic tin compounds and solid fine particles, ensuring stable sliding performance and preventing particle separation into medical agent solutions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If silicone oil or lubricant is applied to the sliding portion of the gasket or syringe to enhance sliding performance, then sliding performance and flow accuracy are improved, but the medical agent solution deteriorates due to interaction with the lubricant over time

Engineering Contradiction:
Improvesliding performanceVSAvoidmedical agent solution stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The invention extracts and removes the lubricant (silicone oil) from the system by using a gasket material (fluororesin) that inherently provides low friction and sliding performance without requiring additional lubricants. This eliminates the harmful interaction between lubricant and medical agent solution while maintaining reliable sliding performance.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the material parameter of the gasket from conventional materials requiring lubrication to fluororesin, which has inherently low friction coefficients and excellent chemical inertness. This parameter change allows the system to achieve both good sliding performance and long-term stability of the medical agent solution without lubricant interaction.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If fluorine resin coating is applied to the gasket surface to eliminate lubricant use, then medical agent solution stability is improved, but sliding performance may be insufficient under high pressure conditions

Engineering Contradiction:
Improvemedical agent solution stabilityVSAvoidsliding performance
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The invention uses fluororesin, a composite material that combines the benefits of low friction coefficients with excellent chemical inertness and stability. This material provides both the required sliding performance under high pressure conditions and the chemical stability needed to prevent interaction with medical agent solutions, resolving the contradiction between these two requirements.

Inventive Principle:
Principle #40Composite materials

3Ease of manufacture

If organic tin compounds are used as catalysts in the coating process, then coating formation is achieved, but environmental and health concerns arise

Engineering Contradiction:
Improvecoating formationVSAvoidenvironmental and health impact
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The invention replaces the harmful organic tin compound catalyst with alternative catalyst systems that are environmentally friendly and safe for medical applications. This substitution eliminates the harmful factors while maintaining the ability to form the fluororesin coating, effectively converting a harmful manufacturing process into a safe one.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

4Reliability

If fine solid particles are added to the coating composition to improve sliding properties, then sliding performance is enhanced, but particles may separate into the medical agent solution causing contamination

Engineering Contradiction:
Improvesliding performanceVSAvoidparticle contamination
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The invention extracts and removes the fine solid particles from the coating composition, relying instead on the inherent properties of fluororesin to provide sliding performance. This eliminates the risk of particle separation and contamination of the medical agent solution while maintaining the necessary sliding characteristics through the material's low friction properties.

Inventive Principle:
Principle #2Taking out (Extraction)

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 provides a stable sliding performance without lubricants, preventing particle separation and ensuring smooth initial motion, while being environmentally friendly by avoiding organic tin compounds, thus enhancing the reliability and safety of medical agent delivery.

Implementation Method 1

a silicone-based resin which is a product of an addition reaction between silicone having at least two vinyl groups and silicone having at least two hydrogen groups bonded to silicon atoms

Methodology Applied
Scientific EffectAddition reaction: Chemical Bonding

Data Source

PatentEP2554205B1Medical device with slideable coating, and syringe
Publication Date: 2020.04.22 TERUMO KK
  • EP2554205B1 patent drawingFigure 1~2
  • EP2554205B1 patent drawingFigure 3~4
  • EP2554205B1 patent drawingFigure 5

AI summary

A medical appliance 1 having a slidable coating layer of the present invention moves in contact with an inner surface of a medical member or that of a lumen and has the slidable coating layer 3 formed at a part thereof which contacts the medical member or the lumen. The slidable coating layer 3 is formed of a composition which does not contain solid fine particles and contains a silicone-based resin which is a product of an addition reaction between silicone having a vinyl group and silicone having a hydrogen group bonded to a silicon atom.