Telescopic Needle Shield Preservative Matching

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Solution Overview

Problem

Existing injection devices with reusable needle cannulas face contamination issues as sterilizing fluid from the telescopic shield can flow into the pharmaceutical liquid cartridge, mixing with the drug and being injected along with it during subsequent uses.

Innovation Solution

An injection device design where the telescopic needle shield contains a preservative-matched cleaning liquid, preventing contamination by ensuring the same preservatives are present in both the cartridge and the cleaning liquid, and using a resilient member to automatically position the needle cannula for cleaning between injections without cumbersome valves.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a telescopic shield with reservoir containing sterilizing fluid is used to clean the needle cannula between injections, then the needle cannula is cleaned and sterilized, but the sterilizing fluid can flow through the lumen of the needle cannula into the cartridge interior and contaminate the pharmaceutical liquid drug

Engineering Contradiction:

Improvesterilization effectivenessVSAvoiddrug contamination

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the chemical composition parameters of the cleaning fluid by formulating it with the same preservatives as the pharmaceutical product. This parameter matching prevents contamination because the cleaning fluid becomes chemically identical to the drug solution, eliminating the harmful effect of contamination while maintaining sterilization effectiveness

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention converts the potentially harmful sterilizing fluid into a beneficial cleaning agent by matching its preservative composition to the pharmaceutical product. The fluid that could have caused contamination is transformed into a safe cleaning medium that actually protects the needle cannula without harming the drug integrity

Inventive Principle:

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

2Productivity

If the needle cannula is maintained attached to the injection device between injections for repeated use, then convenience and productivity are improved, but the risk of contamination and sterilization requirements increase

Engineering Contradiction:

Improverepeated injection capabilityVSAvoidcontamination risk

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The invention applies preliminary action by automatically cleaning and sterilizing the needle cannula between injections using a resilient member that pushes the cannula into the reservoir. This preliminary sterilization action occurs automatically without user intervention, enabling safe repeated use while maintaining productivity

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The injection device performs self-service sterilization by using its own internal reservoir and resilient member mechanism to automatically clean and sterilize the needle cannula between injections. This self-service capability eliminates the need for external sterilization processes, enabling convenient repeated use while controlling contamination risk

Inventive Principle:

Principle #25Self-service

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

Prevents contamination of the pharmaceutical liquid by maintaining preservative balance, ensuring the cleaning liquid does not significantly raise the preservative concentration in the cartridge, thus maintaining the drug's sterility and effectiveness.

Implementation Method 1

The telescopic needle shield is urged in a distal direction by a resilient member, preferably a compression spring operational located between the telescopic needle shield and the housing

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentEP3378507B1Injection device with a needle cannula

Publication Date: 2020.06.10 NOVO NORDISK AS

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AI summary

The present invention relates to an injection device for injecting a pharmaceutical liquid drug containing a preservative. The injection device comprises a housing (1) supporting a cartridge (20) having an interior chamber (21) holding the pharmaceutical preservative containing liquid drug to be injected, and a needle cannula (10) having a front part (11) and a back part (12), which back part (12) is adapted to be in liquid communication with the interior chamber (21) of the cartridge (20). The injection device is further provided with a telescopic needle covering shield (30) which distally is provided with a reservoir (31) which holds a liquid containing the same preservatives as in the pharmaceutical preservative containing liquid drug contained in the interior chamber of the cartridge. The telescopic needle covering shield (30) is telescopic movable in relation to the needle cannula (10) by a first resilient member between a first position and a second position. In the first position, the tip (13) of the front part (11) of the needle cannula (10) is maintained inside the reservoir (31), and in the second position, the tip (13) of the front part (11) of the needle cannula (10) is located outside the reservoir (31) and distally to the reservoir (31). The tip (13) of the needle cannula (10) is thus cleaned by the preservatives in the reservoir (31) between subsequent injections.