Lubricating Eye Drop Composition With Low-Irritation Preservation
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Solution Overview
Problem
Existing ophthalmic solutions lack sufficient lubricating property, preservative efficacy, and can cause eye irritancy, especially when used on damaged or dry corneas.
Innovation Solution
An ophthalmic solution containing a 2-methacryloyloxyethyl phosphorylcholine-dimethylacrylamide-stearyl methacrylate copolymer, polyhexamethylene biguanide, and polyoxyethylene polyoxypropylene glycol, with specific ratios and sodium chloride content, to enhance lubrication and preservative efficacy while reducing eye irritancy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polyhexamethylene biguanide is used as a preservative to ensure sufficient preservative efficacy, then preservative efficacy is improved, but eye irritancy increases especially on damaged or dry corneas
Solution Approach 1:
The patent introduces phosphorylcholine-containing polymers as intermediary substances that mediate between the preservative (polyhexamethylene biguanide) and the corneal surface. These polymers form a protective film on the cornea, reducing direct contact between the preservative and corneal tissues, thereby maintaining preservative efficacy while minimizing eye irritancy on damaged or dry corneas
2Ease of operation
If a sufficient amount of ternary copolymer containing phosphorylcholine group is blended to improve lubricating property, then lubricating property is improved, but preservative efficacy may be reduced
Solution Approach 1:
The patent optimizes the concentration parameters of both the ternary copolymer containing phosphorylcholine group and polyhexamethylene biguanide within specific ranges. By precisely controlling these concentration parameters, the formulation achieves sufficient lubricating property while maintaining preservative efficacy, resolving the trade-off between these two functions
3Quantity of substance
If sodium chloride content is increased to improve moisture-retaining property, then moisture-retaining property is improved, but preservative activity of polyhexamethylene biguanide is reduced
Solution Approach 1:
The patent controls the sodium chloride content within a specific range (0.02-0.60% w/v) and optimizes it in combination with the concentrations of phosphorylcholine-containing polymer and polyhexamethylene biguanide. This parameter optimization ensures sufficient moisture-retaining property while maintaining preservative activity by preventing excessive salt concentration that would reduce preservative effectiveness
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 provides high lubricating property and preservative efficacy with reduced eye irritancy, suitable for damaged or dry corneas.
Implementation Method 1
a technique for improving lubricating property and moisture-retaining property by blending a polymer containing a phosphorylcholine group in an ophthalmic solution is known
Implementation Method 2
an ophthalmic solution used for dry eye is required to have moisture-retaining property for suppressing evaporation of a tear
Implementation Method 3
a preservative is blended in order to prevent contamination of bacteria in the container
Data Source
AI summary
A ophthalmic solution of the present invention contains: (A) 0.02 w/w% or more and 0.15 w/w% or less of a 2-methacryloyloxyethyl phosphorylcholine-dimethylacrylamide-stearyl methacrylate copolymer, in which a molar ratio of constitutional units represented by formula (1) is a:b:c=100:10 to 400:2 to 50; (B) 0.000001 w/w% or more and 0.0001 w/w% or less of polyhexamethylene biguanide represented by formula (2) or a salt thereof; and (C) 0.02 w/w% or more and 2.0 w/w% or less of polyoxyethylene polyoxypropylene glycol, in which a content of sodium chloride is 0.3 w/w% or less. According to the present invention, an ophthalmic solution having sufficient preservative efficacy and less eye irritancy while imparting lubricating property to a corneal surface can be provided.