Study on the Carrier Function and Skin Permeability of Nanoemulsion in Sunscreen and Skin Care Products

Abstract

In this study, nanoemulsion was prepared by high-pressure homogenization method, and its carrier mechanism, skin penetration law and safety in sunscreen products were systematically evaluated, which provided theoretical and practical basis for the design of high-efficiency and low-irritation sunscreen formula. The experimental results show that the nanoemulsion (particle size 150±20 nm) has excellent sun protection performance, SPF value is 50±3, which is about 67% higher than that of traditional emulsion, and the critical wavelength is 382 nm, which meets the broad-spectrum protection standards. At the same time, it showed excellent light stability and water resistance. The residual rate of Avobenzone reached 92% after illumination, and the SPF retention rate exceeded 85% after 40 minutes of water bath. The particle size of nanoemulsion significantly affects the skin penetration behavior, in which the 200 nm emulsion has the highest retention in the stratum corneum (98.7%) and the dermal penetration is only 0.2%. In addition, nanoemulsion showed good biocompatibility, the survival rate of HaCaT cells was still higher than 90% after 48 hours, and no irritation or allergic reaction was found in EpiDerm™ model and human patch test, indicating that it is suitable for special people such as sensitive skin and children.