Coated Particles with Anchored UV Absorbers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Organic UVB and UVA absorbers used in sunscreens can be absorbed through the skin, leading to potential genotoxicity and endocrine disruption due to their small molecule size, and light-absorbing particles can generate free radicals upon photo-excitation, degrading antioxidants.
Innovation Solution
Development of multifunctional coated particles with UVB, UVA, and visible light absorbers, as well as stabilizers, anchored within a silica-based coating that prevents skin penetration and suppresses free radical generation by integrating these components into the coating of particles like ZnO and TiO2, using organo oxysilane and organo-substituted polysiloxane moieties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If organic UVB and UVA absorbers are used in sunscreens, then photoprotection is provided, but skin absorption occurs leading to genotoxicity and endocrine disruption
Solution Approach 1:
The patent segments the photoprotective function from the harmful small-molecule absorbers by attaching UV filters to particle surfaces. The UV absorbers are divided into discrete coating layers on particle cores, preventing their absorption as free small molecules while maintaining their photoprotective function at the particle interface.
Solution Approach 2:
The patent introduces particles as intermediary carriers that host UV absorbers on their surfaces. These particles act as mediators between the UV filter molecules and the skin, allowing the filters to provide photoprotection without being absorbed into the skin, thereby eliminating toxicity while maintaining efficacy.
2Reliability
If light-absorbing particles are used for photoprotection, then UV filtering is enhanced, but free radicals are generated upon photo-excitation degrading antioxidants
Solution Approach 1:
The patent converts the harmful free radical generation by light-absorbing particles into a beneficial system by coating particles with UV absorbers that prevent photo-excitation of the core particles. The harmful photoreactivity is transformed into useful UV filtering by the coating materials, while the core particles provide structural support and dispersion.
Solution Approach 2:
The patent applies preliminary anti-action by using UV absorber coatings that preemptively absorb UV radiation before it can reach and photo-excite the core particles. This preliminary absorption prevents the generation of free radicals from the core particles, protecting antioxidants and other sensitive components in the formulation.
3Reliability
If particles are coated with multiple functional components, then photoprotection and stability are enhanced, but manufacturing complexity increases
Solution Approach 1:
The patent merges multiple functional components (UV absorbers, stabilizers, and dispersants) into a single integrated coating layer on particle surfaces. This combining approach achieves multifunctional performance while simplifying the overall formulation process, as the coating provides simultaneous photoprotection, stability, and dispersion functionality in one step.
Solution Approach 2:
The patent creates universal particle coatings that perform multiple functions simultaneously: UV absorption, photostability enhancement, and improved particle dispersion. This multi-functionality reduces the need for separate additives and simplifies the formulation complexity while achieving comprehensive performance benefits.
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 coated particles provide efficient photoprotection while preventing skin absorption and reducing photoreactivity, enhancing the activity of antioxidants by suppressing free radical formation, thereby improving skin health and reducing degradation of photo-sensitive ingredients.
Implementation Method 1
organo oxysilane and organo-substituted polysiloxane moieties
Implementation Method 2
contains UVB, UVA, and visible light absorbers as well as stabilizers integrally grafted into the coating
Implementation Method 3
suppression of free radical species that are normally generated following photo-excitation of a wide band gap semiconductor particle
Data Source
AI summary
A coated powder comprises (a) particles, and (b) a coating, on the surface of the particles. The surface coating comprises (1) optionally silica moieties, (2) organo oxysilane moieties selected from the group consisting of mono-organo oxysilane moieties, bi-organo oxysilane moieties and tri-organo oxysilane moieties, and (3) optionally organo-substituted polysiloxane moieties. The organo oxysilane moieties each have the formula R′nSiO4-n, with n=1, 2 or 3, and each R′ group is independently selected from the group consisting of alkyl, alkenyl, alkynyl, esters, amides, and at least one aromatic moiety having an absorption band maximum in the region of 280 nm to 780 nm.