ORGS2-0543
Microstructured Organic Sunscreen Emulsions with Enhanced SPF and Reduced Skin Penetration
Topic
GS2. Graduate Student Oral Session II: Functional Biomaterials and Cosmetic Polymer Engineering
When and Where
Sep 28, 2026
16:24 - 16:36
Room 102
Session Chairs
Chaenyung CHA
Ilkoo NOH
Jun Shik CHOI
Presenter(s)
Jaeyeong Kwon (Pohang University of Science and Technology (POSTECH))
Co-Author(s)
Abstract
Organic UV filters are widely used in sunscreen formulations due to their strong UV absorption and formulation versatility. However, simply increasing UV filter loading often leads to limited formulation stability, sensory properties, regulatory constraints, and raise of concerns related to skin permeation. In this work, we report an oil-phase microenvironment engineering strategy using poly(C10-30 alkyl acrylate) (PCAA) and glyceryl monooleate (GMO) in sunscreen emulsions. PCAA, a hydrophobic polymer, enhanced sunscreen performance by structuring the oil phase and improving the dispersion state of organic UV filters, thereby suppressing microaggregation that can impair effective UV absorption. The addition of GMO further amplified this effect only in the presence of PCAA, increasing the in vitro sun protection factor from 30.0 to 53.7 without increasing the total amount of UV filters. This PCAA-dependent enhancement suggests a synergistic interaction between GMO-associated local microstructures and the polymer-structured oil-phase environment, rather than a simple amphiphile effect. Structurally related amphiphilic additives showed only limited enhancement. The GMO-containing formulation also reduced UV filter permeation into human skin, as evidenced by Raman depth profiling and fluorescence imaging. The combined performance enhancement and permeation reduction suggest that GMO-associated amphiphilic domains are stabilized within the PCAA-structured oil phase, reducing UV filter mobility and aggregation while promoting topical retention. This work highlights oil-phase microenvironment engineering as a practical formulation principle for controlling the optical performance and skin transport of hydrophobic active molecules in emulsion systems.
