Water-in-oil emulsion stability using composite surfactants
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing water-in-oil emulsions for topical use face stability issues during storage, especially with nonsteroidal anti-inflammatory agents like NSAIDs, leading to separation and instability at varying temperatures, and often employ volatile silicone derivatives or those causing unpleasant skin sensations.
Innovation Solution
A pharmaceutical composition comprising 60-80% gelled aqueous phase with NSAIDs and 20-40% fatty phase using a combination of alkyl polyglycosides and polyglycerol esters as emulsifying surfactants, ensuring stability and homogeneity at ambient and elevated temperatures for at least three months.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If water-in-oil emulsions are used for topical delivery of NSAIDs, then both water-soluble and liposoluble substances can be conveyed, but the emulsions exhibit stability problems during storage and cannot maintain a stable water-in-oil form
Solution Approach 1:
The patent uses a composite emulsifying system combining two different types of surfactants (nonionic and anionic) in specific proportions. This composite approach creates synergistic effects that enhance both the stability and versatility of the water-in-oil emulsion, allowing it to maintain its structure while delivering both water-soluble and liposoluble NSAIDs effectively
Solution Approach 2:
The patent optimizes specific parameters including the HLB values of surfactants (combining surfactants with complementary HLB ranges), the ratio of aqueous to fatty phase (60-80% vs 20-40%), and storage temperature conditions. These parameter adjustments enable the emulsion to maintain stability across varying temperatures while preserving its dual solubility capability
2Stability of the object's composition
If volatile silicone derivatives are used in water-in-oil emulsions, then emulsion stability is improved, but harmful effects on the environment and users occur
Solution Approach 1:
The patent replaces persistent volatile silicone derivatives with biodegradable, environmentally friendly surfactants that break down harmlessly after use. These alternative surfactants provide sufficient emulsion stability during the product's shelf life and application period without creating long-term environmental contamination
Solution Approach 2:
The patent transforms the challenge of avoiding harmful substances into an opportunity by selecting surfactants that not only eliminate environmental harm but also provide enhanced benefits such as improved skin compatibility, reduced irritation, and maintained emulsion stability through the synergistic combination of nonionic and anionic components
3Object-affected harmful factors
If less volatile silicone derivatives are used in water-in-oil emulsions, then environmental harm is reduced, but unpleasant sensorial properties such as sticky sensations on the skin occur
Solution Approach 1:
The patent applies different functional properties to different components of the emulsion system. The nonionic surfactant component provides the sensorial benefits (lightweight feel, non-sticky texture) while the anionic surfactant component contributes to emulsion stability and skin compatibility. This local differentiation of functions allows the formulation to achieve both environmental safety and pleasant application characteristics
4Ease of manufacture
If conventional emulsifying systems are used in water-in-oil emulsions with NSAIDs, then manufacturing is simplified, but the emulsions separate and become unstable at varying temperatures
Solution Approach 1:
The patent creates a dynamic emulsifying system that adapts to temperature variations. The combination of nonionic and anionic surfactants with complementary temperature profiles allows the emulsion to maintain its water-in-oil structure across a wide temperature range (4°C to 40°C). The system dynamically adjusts its interfacial properties in response to temperature changes, preventing separation while maintaining manufacturability
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 maintains a stable water-in-oil form, preventing separation and skin irritation, while ensuring effective delivery of anti-inflammatory agents, enhancing therapeutic efficacy and patient comfort.
Implementation Method 1
a pharmaceutical composition for topical use which is in the form of an emulsion of water-in-oil type
Implementation Method 2
an emulsifying system comprising a combination of at least one emulsifying surfactant (S1) selected from the elements of the group consisting of compositions of alkyl polyglycosides, and compositions of alkyl polyglycosides and of fatty alcohols, and of at least one emulsifying surfactant (S2) selected from the elements of the group consisting of polyglycerol esters
Data Source
AI summary
A pharmaceutical composition for topical use which is in the form of a water-in-oil emulsion including, for 100% of the weight thereof: —from 60% to 80% by weight of a gelled aqueous phase including an anti-inflammatory substance, —from 20% to 40% by weight of a fatty phase including at least one oil and an emulsifying system including a combination of at least one emulsifying surfactant selected from the elements of the group consisting of alkylpolyglycoside compositions and alkylpolyglycoside and fatty alcohol compositions, and of at least one emulsifying surfactant selected from the elements of the group consisting of polyglycerol esters, alkoxylated polyglycerol esters, polyglycol polyhydroxystearates, polyglycerol polyhydroxystearates and alkoxylated polyglycerol polyhydroxystearates.