Ophthalmic Sterilization Solution for Poly(oxyalkylene) Hydrogels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Poly(oxyalkylene)-containing polymers used in ophthalmic devices are susceptible to oxidative degradation and autoclave-induced haziness, which affects their optical properties and limits their application in ophthalmic devices.
Innovation Solution
An aqueous solution with organic buffer agents like TRIS and organic tonicity-adjusting agents such as glycerol is used for sterilization and storage, reducing autoclave-induced haziness by maintaining a physiological pH and osmolarity, thereby stabilizing the poly(oxyalkylene)-containing polymeric materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If poly(oxyalkylene)-containing polymers are used in ophthalmic devices, then biocompatibility is improved, but susceptibility to oxidative degradation and autoclave-induced haziness increases
Solution Approach 1:
The patent introduces an aqueous solution containing organic buffer agents (TRIS, HEPES, MOPS, or PIPES) and organic tonicity-adjusting agents (glycerol, sorbitol, xylitol, or mannitol) as an intermediary medium between the poly(oxyalkylene)-containing polymer and the autoclave sterilization process. This solution acts as a protective environment that prevents direct harmful interaction between the polymer and harsh sterilization conditions, thereby reducing autoclave-induced haziness while maintaining biocompatibility
Solution Approach 2:
The patent changes the chemical parameters of the storage and sterilization medium by using organic buffer agents and organic tonicity-adjusting agents instead of conventional inorganic buffers and salts. This parameter change creates a chemically compatible environment that prevents oxidative degradation and maintains optical clarity during autoclave sterilization, resolving the contradiction between biocompatibility and resistance to harmful factors
2Reliability
If conventional sterilization methods are used, then sterilization is achieved, but autoclave-induced haziness adversely affects optical properties
Solution Approach 1:
The aqueous solution with organic buffer agents and organic tonicity-adjusting agents serves as a protective intermediary during autoclave sterilization. This medium allows the sterilization process to occur while preventing direct thermal and chemical damage to the polymer matrix that would otherwise cause haziness, thus maintaining optical properties during sterilization
Solution Approach 2:
The patent applies preliminary action by pre-immersing the ophthalmic device in the specially formulated aqueous solution containing organic buffer agents and organic tonicity-adjusting agents before autoclave sterilization. This preliminary placement of the device in a protective environment prevents haziness formation during the subsequent sterilization process, preserving optical clarity
3Adaptability or versatility
If poly(oxyalkylene)-containing polymers are stabilized against oxidative degradation, then applications are increased, but susceptibility to autoclave-induced haziness remains
Solution Approach 1:
The patent introduces the aqueous solution with organic buffer agents and organic tonicity-adjusting agents as a protective intermediary specifically for the autoclave sterilization process. This intermediary protects the polymer from thermal and chemical damage during sterilization that would cause haziness, thereby enabling the polymer's use in ophthalmic devices requiring sterilization while maintaining the expanded applications from oxidative stabilization
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 significantly reduces the susceptibility to oxidative degradation and autoclave-induced haziness, enhancing the stability and optical clarity of ophthalmic devices like contact lenses, ensuring they remain safe and effective for use.
Implementation Method 1
poly(oxyalkylene)-containing polymers may be susceptible to oxidative degradation
Implementation Method 2
autoclave-induced haziness may adversely affect the optical properties of an ophthalmic device
Data Source
AI summary
The present invention provides an aqueous solution for sterilizing and storing ophthalmic devices, preferably a contact lens, made of a hydrogel material, preferably a poly(oxyalkylene)-containing hydrogel material. The solution comprises one or more organic buffer agents, such as a Good buffer or a bis-aminopolyols; an organic tonicity-adjusting agent with multiple hydroxyl groups in an amount sufficient to provide an osmolarity of from about 200 to about 450 mosm/l, wherein the aqueous solution has a pH of from about 5.5 to about 8.5, provided that the aqueous solution include phosphate buffer at a concentration of about 15 mM or less and about 5000 ppm sodium chloride. The present invention also provides a method for sterilizing and storing an ophthalmic device using an aqueous solution of the invention.