Heat-sterilized Chitosan-Glycerol Solution for Ophthalmic Use
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Solution Overview
Problem
Current chitosan compositions are not stable, clear, and viscous at neutral pH after heat sterilization, making them unsuitable for pharmaceutical use, particularly for ophthalmic applications.
Innovation Solution
A process involving solubilizing water-insoluble chitosan in an aqueous solution of a weak acid, adding glycerol, adjusting the pH with a weak base, and steam sterilizing to create a clear and viscous solution at a pH between 6 and 7.5, preventing aggregate formation and ensuring stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chitosan is heat-sterilized in aqueous solution, then sterilization is achieved, but aggregates form and solution clarity is lost
Solution Approach 1:
The patent applies preliminary action by adjusting the pH to acidic conditions (pH 2-4) before heat sterilization. This pre-adjustment prevents aggregate formation during sterilization by ensuring chitosan remains in its soluble protonated form, thereby maintaining solution clarity while achieving sterilization.
2Adaptability or versatility
If pH is adjusted to neutral range (6-7.5), then physiological compatibility is improved, but chitosan precipitation occurs
Solution Approach 1:
The patent applies parameter changes by carefully controlling the final pH within the specific range of 6-7.5 after sterilization. This optimized pH range allows the solution to achieve physiological compatibility while maintaining chitosan solubility and preventing precipitation, thus ensuring both adaptability and compositional stability.
3Productivity
If chitosan concentration is increased for desired viscosity, then therapeutic efficacy is improved, but aggregate formation increases
Solution Approach 1:
The patent applies preliminary action by adjusting pH to acidic conditions before heat sterilization and maintaining this control throughout the process. This pre-established acidic environment prevents aggregate formation even at higher chitosan concentrations required for therapeutic viscosity, thereby achieving both productivity and compositional stability.
4Reliability
If heat sterilization is applied to existing chitosan formulations, then sterility is achieved, but solution stability and clarity are compromised
Solution Approach 1:
The patent applies preliminary action by adjusting the pH to acidic conditions (pH 2-4) before heat sterilization. This pre-adjustment ensures chitosan remains in its soluble form during the sterilization process, preventing aggregate formation and maintaining solution stability and clarity while achieving sterility.
Solution Approach 2:
The patent applies parameter changes by optimizing the pH range after sterilization to 6-7.5. This controlled parameter adjustment ensures the final formulation achieves both sterility and long-term solution stability, preventing precipitation while maintaining therapeutic efficacy.
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 process results in a stable, clear, and viscous chitosan-glycerol solution suitable for pharmaceutical use, particularly for ophthalmic applications, effectively addressing the challenges of aggregate formation and stability issues in existing compositions.
Implementation Method 1
Solubilizing chitosan having an average molecular weight ranging from 10 kDa to 250 kDa and a degree of deacetylation higher than 60% in an aqueous solution of weak acid comprising a carboxylic group
Implementation Method 2
Steam sterilizing; thereby forming a heat-sterilized composition comprising solubilized chitosan and glycerol that is a clear and viscous solution
Data Source
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AI summary
The present invention relates to a heat-sterilized aqueous composition comprising a solubilized chitosan and glycerol. It also relates to a process of preparation of the same, as well as the use thereof, including compositions useful for the prevention and treatment of dry eye syndrome and arthritic diseases or disorders.