Cosmetic Emulsion Stability with Urea Derivatives
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Solution Overview
Problem
Water-containing emulsions used in cosmetics, particularly those containing N-functionalized urea derivatives, face stability issues over a wide temperature range and require additional stabilizers like thickening polymers to maintain emulsion stability.
Innovation Solution
A cosmetic emulsion formulation comprising a urea derivative of specific formula, a salt of C12-20 alkyl phosphate, and C14-20 mono- or diacylglycerides, which provides excellent stability without the need for additional stabilizers, maintaining viscosity and stability over several months across a broad temperature range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If urea derivatives with hydroxy-functionalized substituents are added to provide moisturizing effect, then moisturizing performance is improved, but emulsion stability deteriorates
Solution Approach 1:
The patent introduces a specific emulsifier combination (nonionic emulsifier with HLB 4-8 and cationic emulsifier) as an intermediary system that mediates between the moisturizing urea derivatives and the emulsion structure. This emulsifier combination acts as a bridge that allows the urea derivatives to maintain their moisturizing function while the emulsifiers stabilize the emulsion interface, preventing phase separation.
Solution Approach 2:
The patent creates a composite emulsion system combining multiple components: urea derivatives (moisturizers), specific emulsifier combination (stabilizers), and other cosmetic ingredients. This composite approach allows the system to simultaneously achieve moisturizing performance from urea derivatives and emulsion stability from the synergistic emulsifier combination, resolving the contradiction between these two functions.
2Stability of the object's composition
If thickening polymers are added as stabilizers to restore emulsion stability, then emulsion stability is improved, but formulation complexity increases
Solution Approach 1:
The patent changes the parameters of the emulsifier system by selecting specific types (nonionic with particular HLB range and cationic emulsifiers) with defined properties. This parameter optimization allows the emulsifiers alone to provide sufficient stability, eliminating the need for additional thickening polymers and simplifying the formulation while maintaining emulsion stability across temperature ranges.
3Stability of the object's composition
If additional stabilizers like thickening polymers are incorporated to maintain stability, then emulsion stability is improved, but viscosity control becomes more difficult
Solution Approach 1:
The specific emulsifier combination acts as an intermediary that provides stability without significantly affecting viscosity. By using emulsifiers that stabilize at the interface without forming thickening networks, the patent achieves emulsion stability while maintaining controllable viscosity, avoiding the need for thickening polymers that would complicate viscosity control.
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 emulsion remains stable from -10°C to 60°C for at least 12 weeks, retaining viscosity and eliminating the need for thickening polymers, ensuring long-term product stability and performance.
Implementation Method 1
oil or fat components are used to care for the substrate, especially the skin or hair. On the other hand, oil-soluble active ingredients in oils or fats, such as UV filters, can be incorporated into a water-based cosmetic in dissolved form
Implementation Method 2
incorporated into water-based cosmetics in the form of an emulsion with the help of emulsifiers
Implementation Method 3
N-functionalized urea derivatives with hydroxy-functionalized substituents as a moisturizer that is particularly suitable for use in cosmetics
Implementation Method 4
humectants (hereinafter referred to as moisturizers) that supply moisture to the substrate
Data Source
AI summary
The invention relates to cosmetic compositions in the form of an emulsion, comprising: a) at least one urea derivate selected from at least one compound according to formula (I), wherein groups R1, R2, R3 and R4 stand independently from one another for a hydrogen atom, a C1-C4 alkyl group, a C2-C6 alkylene group or a C2-C6 hydroxy alkyl group comprising at least one hydroxyl group, provided that at least one of the said groups stands for a C2-C6 hydroxy alkyl group comprising at least one hydroxyl group and b) at least one salt of C12-20 alkyl phosphate, in particular a salt of cetyl phosphate, and c) at least one C14-20-mono or diacylgrycerid, preferably at least one C16-18 mono- or diacylglyerid, particularly preferably selected from hardened palm oil glycerides, and d) water. Said emulsions are storage-stable and have a stable viscosity.