Anhydrous Retinol Oil Composition with Low Irritation
Solution Overview
Problem
Existing retinol-based cosmetic compositions, particularly oil-in-water emulsions, require specific weight ratios of polar emollients to isohexadecane for optimal retinol activity and low irritation, which differ from those needed in anhydrous compositions, limiting the formulation options for effective skin aging and other skin issues.
Innovation Solution
An anhydrous composition containing 0.05 to 0.5% retinol, a polar emollient such as propylene glycol stearyl ether or dicaprylyl carbonate, and isohexadecane, with a weight ratio of polar emollient to isohexadecane of 1:1 or lower, providing a cosmetically effective and low-irritation treatment for skin aging, stretch marks, cellulite, acne, and rosacea.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oil-in-water emulsion formulation is used with retinol, then retinol activity is improved, but formulation complexity increases and requires specific weight ratios of polar emollient to isohexadecane (75:25 to 50:50)
Solution Approach 1:
The patent extracts water from the oil-in-water emulsion system to create an anhydrous formulation. This removes the need for water-based emulsification while maintaining retinol delivery effectiveness, thereby simplifying the formulation structure without sacrificing reliability
Solution Approach 2:
The patent inverts the weight ratio parameter of polar emollient to isohexadecane from the conventional 75:25 to 50:50 range to a new range of 50:50 to 90:10. This parameter change enables effective retinol delivery in anhydrous conditions, resolving the contradiction by finding new optimal values that work without water
2Device complexity
If anhydrous composition is used with inverted weight ratio of polar emollient to isohexadecane (1:1 or lower), then formulation simplicity is improved, but deviation from conventional ratios may reduce effectiveness
Solution Approach 1:
The patent systematically changes the weight ratio parameter of polar emollient to isohexadecane to the 50:50 to 90:10 range, which has been optimized for anhydrous conditions. This parameter optimization ensures that the simplified anhydrous formulation maintains high retinol activity despite departing from conventional emulsion ratios
Solution Approach 2:
The anhydrous formulation serves itself by using only oil-based components (isohexadecane and polar emollient) to deliver retinol, eliminating the need for water and emulsifying agents. This self-contained system achieves both simplicity and effectiveness
Data Source
AI summary
The present invention provides a composition comprising (i) 0.05 to 0.5 % by weight retinol; (ii) a polar emollient selected from the group consisting of propylene glycol stearyl ether, dicaprylyl carbonate, propylene glycol isostearate and combinations thereof; and (iii) isohexadecane, wherein the weight ratio of polar emollient to isohexadecane is 1:1 or lower and the composition is anhydrous.