Injection Barrel Lubricant Control for Subvisible Particle Reduction
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Solution Overview
Problem
The migration of lubricant coating droplets into the 'dead space' and implantation channel of medical injection devices leads to the formation of subvisible particles, exceeding regulatory limits, which can affect drug quality and stability.
Innovation Solution
A method to limit lubricant deposition into the region extending distally from the distal end of the barrel by controlling the application process, ensuring the lubricant coating is confined to the inner barrel walls, thereby reducing the amount of subvisible particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If lubricant coating is applied to the inner wall of the barrel to improve stopper sliding, then the stopper slides more smoothly, but subvisible particles are generated that exceed regulatory limits
Solution Approach 1:
The patent applies local quality by creating a lubricant-free zone in the dead space region while maintaining lubricant coating on the barrel inner wall. This is achieved by controlling the deposition process to limit lubricant only to areas where the stopper accesses, leaving the distal region extending from the barrel distal end free of lubricant coating. This resolves the contradiction by providing lubrication where needed for stopper sliding while eliminating particle generation in the dead space.
2Ease of manufacture
If lubricant coating is deposited by spraying or dipping, then the barrel surface is lubricated, but lubricant migrates into the dead space forming subvisible particles
Solution Approach 1:
The patent applies parameter changes by modifying the deposition process parameters to control lubricant placement. Specifically, the method limits lubricant deposition into the dead space region by adjusting spray parameters, dip depth, or other deposition conditions. This changes the spatial distribution parameter of lubricant coating, concentrating it in the barrel region while excluding the dead space, thereby maintaining ease of manufacture while preventing particle formation.
3Ease of operation
If the barrel is lubricated to improve stopper movement, then injection operation is facilitated, but drug quality and stability are compromised by particle contamination
Solution Approach 1:
The patent applies the extraction principle by removing lubricant from the dead space region where it would contaminate the pharmaceutical composition. The method specifically extracts or prevents lubricant deposition in the distal region extending from the barrel, while maintaining lubricant coating on the barrel inner wall. This separates the lubrication function from the drug storage function, ensuring smooth injection operation while protecting drug quality from contamination.
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 method effectively reduces subvisible particles to below regulatory limits, enhancing drug quality and stability by minimizing lubricant migration into non-accessible regions.
Implementation Method 1
In contact with the pharmaceutical composition, the lubricant coating can migrate into the filling solution under the form of lubricant droplets of various sizes
Data Source
AI summary
The invention relates to a method for reducing an amount of sub visible particles in a pharmaceutical composition contained in a medical injection device comprising a container (1) including a barrel (10) lubricated with a lubricant coating (2) in contact with the pharmaceutical composition, and a stopper (14) in sliding engagement within the barrel (10), the container comprising a region (130, 121, 123) extending distally from the distal end (100) of the barrel which is not accessible to the stopper. During formation of said lubricant coating (2) on the inner wall of the barrel, the method comprises limiting lubricant from being deposited into said region (130, 121, 123) extending distally from the distal end (100) of the barrel.