Prefilled Syringe Plunger Pathway for Stopper Interface Sterilization
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Solution Overview
Problem
Existing prefilled syringes face challenges in achieving complete external surface sterilization, particularly around the plunger and stopper interface, due to difficulties in accessing these areas with sterilizing agents and pressure variations during sterilization, which can lead to contamination risks.
Innovation Solution
The design of a prefilled syringe with a plunger that forms a pathway for sterilizing agents to reach the stopper interface, combined with a backstop mechanism to prevent excessive stopper movement during sterilization, ensuring comprehensive external surface sterilization and maintaining sterility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the plunger is designed to be tightly coupled to the stopper to prevent contamination, then sterility is improved, but access for sterilizing agents to the interface area becomes difficult
Solution Approach 1:
The patent introduces an intermediary channel or pathway formed within the plunger structure that allows sterilizing agents to reach the stopper interface area. This channel acts as a mediator, enabling the sterilizing agent to traverse through the plunger body and contact the stopper surface without compromising the tight coupling between plunger and stopper, thus maintaining sterility while improving accessibility for sterilization.
2Reliability
If pressure variations are applied during sterilization to improve penetration of sterilizing agent, then sterilization completeness is improved, but excessive stopper movement occurs leading to contamination risk
Solution Approach 1:
The patent incorporates a backstop mechanism that provides preliminary resistance to excessive stopper movement before contamination can occur. This backstop structure counteracts the harmful effect of pressure-induced stopper displacement by mechanically limiting the movement range, thereby preventing contamination risk while allowing sufficient pressure variation for sterilizing agent penetration.
3Ease of operation
If the plunger is made with complex internal structures to guide sterilizing agents, then sterilization access is improved, but device complexity increases
Solution Approach 1:
The patent segments the plunger structure into functional zones: an external surface for coupling, an internal channel system for sterilizing agent flow, and a backstop region for movement control. This segmentation allows each component to perform its specific function efficiently - the channel provides sterilization access while the overall plunger design remains relatively simple, avoiding unnecessary complexity.
Data Source
AI summary
A prefilled syringe is disclosed that includes a barrel, a stopper displaceable within and defining a sealed chamber in an interior of the barrel, a liquid filled in the chamber of the barrel, and a plunger extending within the barrel. The stopper expels the liquid out of the barrel via an orifice when being forwarded towards the orifice by the plunger such that a volume of the chamber is reduced. The plunger includes a proximal portion, a distal portion and a rod portion extending between the proximal portion and the distal portion. The plunger is shaped to form a pathway between an opening of the barrel and a segment where the proximal portion of the plunger is neighboring the stopper such that a sterilizing agent can be provided through the opening of the barrel to the segment where the proximal portion of the plunger is neighboring the stopper.