Cationic Silicone Hydrogel Lens for Linear Comfort Agent Release
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Solution Overview
Problem
Existing contact lenses struggle with controlled release of comfort agents, often experiencing either trapped or burst release, which affects comfort and duration of effectiveness.
Innovation Solution
A silicone hydrogel contact lens with a polymeric lens body composed of specific monomer ratios, including siloxane, nonionic hydrophilic, and acyclic tertiary amine monomers, facilitates controlled release of anionic agents through ionic interactions, allowing for sustained release over extended periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If comfort agents are introduced in lens materials or packaging solution, then contact lens comfort is improved, but the release pattern becomes uncontrolled (either trapped or burst release instead of controlled release)
Solution Approach 1:
The patent modifies the chemical parameters of the lens material by incorporating specific cationic monomers (such as 2-(dimethylamino)ethyl methacrylate) at controlled concentrations (0.1-15 wt%). This chemical parameter change creates ionic interactions with anionic comfort agents, enabling controlled release without requiring complex structural modifications to the lens system.
Solution Approach 2:
The patent creates a composite lens material system combining silicone hydrogel base material with cationic functional monomers. This composite approach integrates the oxygen permeability benefits of silicone hydrogel with the controlled release properties of cationic groups, achieving both comfort and functionality without significant added complexity.
2Duration of action of moving object
If comfort agents are released during lens wearing, then comfort is enhanced, but burst release occurs instead of sustained release over extended periods
Solution Approach 1:
The patent achieves continuous release action by establishing ionic bonding between cationic lens material and anionic comfort agents. This continuous ionic interaction provides sustained release over extended wear periods (8+ hours) rather than intermittent or burst release, maintaining consistent comfort throughout the wearing duration.
Solution Approach 2:
By adjusting the concentration and type of cationic monomers in the lens material, the patent controls the release kinetics of comfort agents. This parameter optimization ensures neither trapped nor burst release, but rather a sustained, reliable release pattern consistent throughout the wearing period.
3Use of energy by moving object
If silicone hydrogel material is used, then oxygen permeability is improved, but controlled release of comfort agents becomes difficult
Solution Approach 1:
The patent develops a composite silicone hydrogel material that integrates cationic functional groups within the polymer matrix. This composite structure maintains the high oxygen permeability characteristic of silicone hydrogel while adding the comfort agent retention and controlled release properties of cationic materials, resolving the contradiction between oxygen transport and comfort agent management.
Solution Approach 2:
The patent creates a multi-functional lens material that simultaneously provides oxygen permeability, comfort agent retention, and controlled release. The cationic silicone hydrogel material performs multiple functions - oxygen transport, comfort agent binding, and sustained release - eliminating the need to choose between oxygen permeability and comfort agent control.
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 contact lens achieves a substantially linear release of anionic agents for at least 8 hours, with higher uptake and release capabilities, avoiding burst release and maintaining comfort over time.
Implementation Method 1
A contact lens having cationic properties and method of manufacturing the contact lens are provided. The contact lens provides the ability to controllably release one or more comfort agents or other beneficial agent in the form of releasable anionic agents.
Implementation Method 2
The at least one acyclic tertiary amine monomer facilitates uptake and/or sustained release of the at least one releasable anionic agent by the polymeric lens body.
Implementation Method 3
When the lens is placed on the eye, the comfort agents release to the ocular surface.
Data Source
AI summary
A cationic contact lens is described as well as methods of manufacturing the same. The cationic contact lens includes a polymeric lens body that is the reaction product of a polymerizable composition that includes at least one siloxane, at least one nonionic hydrophilic monomer and at least one acyclic tertiary amine monomer. The cationic contact lens can be an unworn sterile silicone hydrogel contact lens. The contact lens is capable of substantially linear release of a releasable anionic agent and the at least one acyclic tertiary amine monomer facilitates uptake and/or sustained release of the releasable anionic agent by the polymeric lens body. The contact lens can be present in a sealed contact lens package. The sealed contact lens package can include at least a) a base member having a cavity; b) a contact lens packaging solution in the cavity; c) a unworn sterile contact lens immersed in the contact lens packaging solution in the cavity with the releasable anionic agent present; and d) a cover that forms a liquid-tight seal with the base member.