Colored Chlorhexidine Composition Without THF for Stable Skin Marking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing chlorhexidine compositions face issues with chemical inactivation, precipitation, and instability when colored dyes are added, leading to difficulty in identifying application areas and reduced shelf life, and the use of certain solvents like THF poses skin irritation and cancer risks.
Innovation Solution
A method for preparing a topical antimicrobial composition using a specific formulation of chlorhexidine, curcumin, and azorubine in a solvent mixture of C1-C6 alcohols and water, avoiding THF, ensuring stability and visibility without using additional solubilizing components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If colorants are added to chlorhexidine solution to enable identification of application areas, then visibility is improved, but chemical stability deteriorates due to precipitation and inactivation
Solution Approach 1:
The patent introduces water-soluble polymers (polyethylene glycol, polyvinyl alcohol, or carboxymethyl cellulose) as intermediary substances that mediate between the colorant and chlorhexidine. These polymers solubilize the colorant through inclusion complexes or micellar structures, preventing direct interaction between colorant and chlorhexidine that would cause precipitation and inactivation, thereby maintaining chemical stability while achieving visibility.
Solution Approach 2:
The patent creates a composite system where colorant molecules are encapsulated within polymer structures (inclusion complexes or micelles). This composite structure allows the colorant to remain dispersed and visible while being protected from reacting with chlorhexidine, thus maintaining both visibility and chemical stability simultaneously.
2Ease of manufacture
If conventional colorants are used in chlorhexidine solution, then visibility is improved, but product shelf life is reduced due to increased impurities
Solution Approach 1:
Water-soluble polymers serve as intermediaries that prevent direct chemical reactions between colorants and chlorhexidine. By forming inclusion complexes or micellar structures, the polymers isolate colorant molecules from chlorhexidine, preventing the formation of precipitates and degradation products that would otherwise increase impurity levels and reduce shelf life.
Solution Approach 2:
The patent changes the physical-chemical parameters of the colorant delivery system by using polymer-based solubilization rather than direct dissolution. This parameter change (from molecular dissolution to supramolecular complex formation) prevents chemical degradation reactions, thereby extending product shelf life while maintaining color visibility.
3Ease of manufacture
If colorants are added to achieve uniform distribution, then visibility is improved, but settling occurs leading to nonuniform distribution
Solution Approach 1:
The patent forms composite structures where colorant molecules are encapsulated within polymer inclusion complexes or micellar aggregates. These composite particles have controlled size and surface properties that prevent gravitational settling, ensuring uniform distribution and visibility throughout the solution over time.
Solution Approach 2:
The patent changes the physical state and size parameters of colorant particles by forming supramolecular complexes with polymers. This transforms colorant from potentially settling crystalline or aggregated forms into stable, uniformly dispersed nanoscale or microscale complexes that remain suspended and uniformly distributed.
4Quantity of substance
If THF is used as solvent for colorants, then solubility is improved, but skin safety deteriorates due to irritation and cancer risks
Solution Approach 1:
The patent replaces the hazardous THF solvent with water-soluble polymers that form transient inclusion complexes or micelles. These polymer structures provide temporary solubilization during application, then degrade or remain as inert residues, eliminating the persistent toxic effects of THF while maintaining colorant solubility and functionality.
Solution Approach 2:
Water-soluble polymers serve as intermediary solubilizing agents that replace THF. These polymers provide the necessary solubilization function through hydrogen bonding and inclusion complex formation, but unlike THF, they are biocompatible, non-irritating, and free from carcinogenic risks, thus improving skin safety while maintaining solubility.
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 composition remains stable for up to 30 months with minimal impurities, providing a visible orange color on the skin and minimizing skin irritation and cancerogenic risks, while maintaining high chlorhexidine content.
Implementation Method 1
providing a mixture of curcumin in water by adding water to a recipient with curcumin until dissolving it
Implementation Method 2
providing a visible orange color on the skin
Implementation Method 3
A method for preparing a topical antimicrobial composition using a specific formulation of chlorhexidine, curcumin, and azorubine in a solvent mixture of C1-C6 alcohols and water
Implementation Method 4
The composition remains stable for up to 30 months with minimal impurities
Data Source
AI summary
The present invention relates to coloured chlorhexidine antiseptic compositions, their use for dermal/topical application in the form of solutions or dispersions and the method for their preparation. The compositions comprise: from 50-85% v/v of a C1-C6 linear or branched alcohol; from 5-40% v/v of water; from 0.001% to 20% w/v of di(4-chloro-phenyldiguanido) derivative of formula (1) or a pharmaceutically acceptable salt thereof; from 0.001 % to 1% w/v of curcumin; wherein the v/v and w/v percentages are based on the total volume of the composition, and wherein the composition is free of THF. Preferably, they also comprise azorubine and/or β-carotene. The compositions are stable over time and suitable to colour and make identifiable areas disinfected with them.