Hydroxypropylcellulose Viscosity Control in Ethanol Sunscreen Gels
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Solution Overview
Problem
Existing sunscreen gels have limitations in adjusting the sun protection factor (SPF) without increasing UV filter concentration, as SPF adjustment is solely dependent on UV filter content, and high UV filter concentrations lead to unattractive and sticky products with stability issues due to complex molecular structures.
Innovation Solution
A gel-shaped cosmetic preparation containing ethanol, hydroxypropyl cellulose with a molecular weight less than 1000 kg/mol, and specific UV filters, which maintains viscosity and enhances SPF without increasing UV filter concentration, using hydroxypropyl cellulose as a thickener to achieve a predetermined viscosity and improve product attractiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If UV filter concentration is increased to adjust SPF, then sun protection factor is improved, but product stickiness and sensorial attractiveness deteriorate
Solution Approach 1:
The patent changes the molecular weight parameter of hydroxypropylcellulose to less than 1000 kg/mol, which fundamentally alters the thickening mechanism. This allows the formulation to achieve the desired viscosity with lower thickener concentration, thereby reducing the sticky feeling on skin while maintaining product stability and SPF performance.
Solution Approach 2:
The patent creates a composite system combining low molecular weight hydroxypropylcellulose with ethanol and UV filters. This composite approach allows the thickener to work more efficiently at lower concentrations, providing adequate viscosity without the excessive stickiness associated with conventional thickener levels, thus improving sensorial properties while maintaining SPF.
2Reliability
If UV filter concentration is increased to adjust SPF, then sun protection factor is improved, but formulation stability deteriorates
Solution Approach 1:
By changing the molecular weight parameter of hydroxypropylcellulose to less than 1000 kg/mol, the patent achieves a more efficient thickening effect. This allows the formulation to maintain stable viscosity without requiring high concentrations of UV filters, thereby preventing the instability and precipitation issues that occur when UV filters are used in excessive amounts.
Solution Approach 2:
The low molecular weight hydroxypropylcellulose acts as an intermediary substance that mediates between the UV filters and the ethanol base. It provides steric stabilization and prevents UV filter precipitation, allowing higher UV filter concentrations to be used for SPF adjustment without compromising formulation stability.
3Shape
If conventional thickeners are used to achieve desired viscosity, then viscosity is improved, but sun protection factor adjustment becomes limited
Solution Approach 1:
The patent changes the molecular weight parameter of hydroxypropylcellulose to less than 1000 kg/mol, which fundamentally improves the thickening efficiency. This allows the formulation to achieve the desired viscosity with minimal thickener concentration, thereby freeing up formulation flexibility to adjust SPF by varying UV filter concentrations without being constrained by thickener requirements.
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 effectively increases the SPF of sunscreen gels while maintaining transparency and attractiveness, reducing stickiness, and stabilizing UV filters at higher concentrations, providing enhanced skin protection without the drawbacks of prior art products.
Implementation Method 1
hydroxypropylcellulose having a molecular weight of less than 1000 kg/mol... as a thickener to achieve a predetermined viscosity
Implementation Method 2
the ultraviolet radiation from sunlight also has a damaging effect on the skin... These UVA and UVB filters are summarized in most industrialized countries in the form of positive lists
Implementation Method 3
A gel-like cosmetic preparation containing ethanol, one or more UV filters and hydroxypropylcellulose
Data Source
AI summary
The present invention relates to a preferably anhydrous and transparent cosmetic formulation in gel form, comprising ethanol, one or more UV filters and hydroxypropyl cellulose having a molecular weight of greater than 1000 kg/mol, and to a method for increasing the light protection factor by adding the hydroxypropyl cellulose and to the use of the hydroxypropyl cellulose for increasing the light protection factor of a cosmetic formulation in gel form.