Retractable Needle Assembly with Breakable Hub for Leakage-Proof Storage
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Solution Overview
Problem
Current retractable needle syringes are not suitable for long-term storage of injection products, as they are not designed for prefilling and are prone to leakage and drug loss during storage, making them unsuitable for conventional filling processes and long-term shelf life.
Innovation Solution
A needle assembly with a self-standing piston for long-term storage and a retractable needle mechanism, featuring a needle hub and sealing means made of different materials for optimal sealing and handling, allowing for prefilling and long-term storage without leakage or product deterioration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a retractable needle mechanism is integrated into the syringe, then safety against accidental pricking is improved, but the device becomes unsuitable for long-term storage and prefilling
Solution Approach 1:
The syringe is divided into separate functional modules: a storage barrel, a retractable needle assembly, and a piston. The needle assembly can be detached from the barrel, allowing the barrel to be used for long-term storage while the needle provides safety during injection. This segmentation resolves the contradiction by separating the storage function (requiring stability) from the injection function (requiring retractable needle safety).
Solution Approach 2:
A detachable needle assembly acts as an intermediary component between the storage barrel and the user. The needle assembly includes a hub that connects to the barrel and a retractable needle mechanism. This intermediary design allows the barrel to maintain its storage integrity while the needle provides protection during administration, resolving the incompatibility between long-term storage and retractable needle safety features.
2Ease of manufacture
If the needle hub and barrel are made as a single integrated unit, then manufacturing is simplified, but the seal becomes prone to leakage and drug permeation during long-term storage
Solution Approach 1:
The needle hub is segmented from the barrel, allowing independent optimization of each component. The hub can be designed with specific sealing features (such as O-rings or Luer locks) that are separate from the barrel structure. This segmentation enables better sealing performance during long-term storage while maintaining manufacturing simplicity through modular assembly processes.
Solution Approach 2:
The needle hub and barrel are made from different materials with complementary properties: the barrel is made from chemically resistant material (such as polypropylene or glass) while the hub incorporates sealing materials (such as rubber O-rings or thermoplastic elastomers). This composite approach resolves the contradiction by providing superior sealing performance through material diversity while maintaining ease of manufacture through standardized connection interfaces.
3Device complexity
If a stopper is co-injected with the plunger rod, then the filling process is simplified, but the device cannot be used with conventional stopping processes on automatic filling lines
Solution Approach 1:
The stopper and plunger rod are segmented into separate components that can be assembled independently. The stopper can be pre-assembled with the plunger rod in a controlled environment, then the complete assembly is inserted into the barrel. This segmentation allows compatibility with conventional automatic filling lines that use separate stopping processes, while maintaining filling process simplicity through pre-assembly of the stopper-plunger unit.
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 safe, compact, and stable injection device that prevents accidental pricking and product loss, enabling prefillable syringes to be stored for up to three years without deterioration, while being compatible with conventional filling processes.
Implementation Method 1
reduce product permeation
Implementation Method 2
a breakable portion located between said engaging means and said needle-bearing portion, said breakable portion being arranged to, when broken, allow independent proximal displacement of said needle-bearing portion relative to said engaging means
Implementation Method 3
a piston intended to expel said product through the distal end under a distal force exerted on said piston
Data Source
AI summary
The present invention relates to a needle assembly (1) to be used in combination with a storing device (200) comprising a barrel (8) defining a chamber (9) receiving a product (4) and a piston (2), the assembly (1) comprising: —needle-bearing portion (7) in a first material, movable between an exposed and a retracted positions of the needle (5), —engaging means (8a, 10, 11, 18,) for securing said needle-bearing portion (7) to said barrel (8) in the exposed position, characterized in that it comprises: —sealing means (15) in a second material for tightly sealing the distal end (9a) of said chamber (9) to said needle-bearing portion (7), —a breakable portion (7a) located between said engaging means (8a, 10, 11, 18,) and said needle-bearing portion (7), which, when broken, allows independent proximal displacement of said needle-bearing portion (7) relative to said engaging means (8a, 10, 11, 18,) between said exposed and said retracted positions, said first material being more rigid than said second material. The invention also relates to an injection device (100) comprising said needle assembly (1) and a storing device (200).