Silicone Hydrogel Contact Lens Wettability via Extractable Components
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Solution Overview
Problem
Silicone hydrogel contact lenses produced from non-polar resin molds have low wettability and are not ophthalmically compatible, requiring surface treatments or polymeric wetting agents to improve compatibility, which are cumbersome and may degrade over time.
Innovation Solution
A polymerizable composition comprising α-ω-bis(methacryloyloxyethyl iminocarboxy ethyloxypropyl)-poly(dimethylsiloxane)-poly(trifluoropropylmethylsiloxane)-poly(ω-methoxy-poly(ethyleneglycol)propylmethylsiloxane), N-vinyl-N-methylacetamide, methylmethacrylate, ethylene glycol dimethacrylate, allyloxy alcohol, and a free radical initiator, which forms a pre-extracted polymerized silicone hydrogel contact lens with high extractable content, achieving ophthalmically acceptable surface wettability without surface treatments or polymeric wetting agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If silicone hydrogel contact lenses are produced from non-polar resin molds, then the manufacturing process is simple, but the lens surface has low wettability and is not ophthalmically compatible
Solution Approach 1:
The patent applies preliminary action by incorporating hydrophilic extractable components (such as polyvinylpyrrolidone or polyethylene glycol) into the lens material during the manufacturing process, before the lens is used. This pre-incorporation ensures that the lens surface achieves adequate wettability and ophthalmic compatibility from the outset, eliminating the need for post-manufacturing surface treatments while maintaining manufacturing simplicity
Solution Approach 2:
The patent changes the chemical composition parameters of the lens material by incorporating hydrophilic extractable components at specific concentrations (e.g., 1-30% by weight). This parameter change transforms the surface properties of the lens, enabling it to achieve adequate wettability and ophthalmic compatibility while being produced from non-polar resin molds
2Reliability
If surface treatment is applied to improve lens wettability, then ophthalmic compatibility is enhanced, but the manufacturing process becomes more complex and time-consuming
Solution Approach 1:
The patent takes out the hydrophilic properties from separate surface treatment processes and incorporates them directly into the lens material during manufacturing. By extracting the essential function (hydrophilicity) and integrating it into the base material through extractable components, the patent eliminates the need for complex post-manufacturing surface treatment steps
Solution Approach 2:
The patent merges the function of hydrophilic surface treatment with the lens material itself by incorporating extractable hydrophilic components during the manufacturing process. This combination integrates multiple functions (structural integrity and surface wettability) into a single manufacturing step, reducing process complexity
3Reliability
If polymeric wetting agents are used to improve surface wettability, then initial compatibility is enhanced, but the wettability degrades over time with handling and wear
Solution Approach 1:
The patent applies preliminary action by incorporating hydrophilic extractable components during manufacturing that are designed to leach out gradually over time. This gradual release provides sustained wettability enhancement throughout the lens wear period, preventing the degradation that occurs with surface-applied polymeric wetting agents
Solution Approach 2:
The patent ensures continuity of useful action through the controlled leaching of hydrophilic extractable components from the lens material during wear. This continuous release mechanism maintains adequate surface wettability throughout the lens lifespan, providing ongoing beneficial action rather than the initial-only effect of surface treatments
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 produces silicone hydrogel contact lenses with extended wear compatibility, maintaining ophthalmically acceptable surface wettability and comfort for at least a day, week, or month without removal, with improved mechanical properties and reduced extractable content.
Implementation Method 1
A polymerizable composition comprising α-ω-bis(methacryloyloxyethyl iminocarboxy ethyloxypropyl)-poly(dimethylsiloxane)-poly(trifluoropropylmethylsiloxane)-poly(ω-methoxy-poly(ethyleneglycol)propylmethylsiloxane), N-vinyl-N-methylacetamide, methylmethacrylate, ethylene glycol dimethacrylate, allyloxy alcohol, and a free radical initiator, which forms a pre-extracted polymerized silicone hydrogel contact lens
Implementation Method 2
The method produces silicone hydrogel contact lenses with extended wear compatibility, maintaining ophthalmically acceptable surface wettability and comfort for at least a day, week, or month without removal, with improved mechanical properties and reduced extractable content
Data Source
AI summary
Silicone hydrogel contact lenses having ophthalmically acceptable surface wettabilities are obtained from pre-extracted polymerized silicone hydrogel contact lens products produced from a polymerizable composition comprising a combination of particular components. The silicone hydrogel contact lenses can be obtained from non-polar resin based contact lens molds and without surface treatments or an interpenetrating polymeric network of a polymeric wetting agent. Related lens products, polymerizable compositions, and methods are also described.