Aqueous two-phase system as a greener extraction method and the synergistic effects of the herbal mixture for acne-prone skin cosmetic applications

This study focuses on the development of a gentle, antibiotic-free cosmetic approach for acne-prone skin using a herbal mixture composed of Houttuynia cordata, Scutellaria baicalensis, Chamaecyparis obtusa, and Artemisia capillaris. The authors first evaluated an ethanol/ammonium sulfate aqueous two-phase system as a green, polarity-directed extraction method and compared the resulting fractions with the crude extract. Chemical analyses showed that ATPS, especially the N12 fraction, increased phenolic and flavonoid content and improved DPPH radical-scavenging activity. However, zebrafish toxicity and oxidative-stress models demonstrated that the crude extract was safer and more biologically suitable for cosmetic development. Therefore, the crude extract was used to prepare cleanser and spot gel serum prototypes. Both formulations remained physically stable for four weeks, while the cleanser showed clear antibacterial activity and strong inhibition of mono- and mixed-species biofilm formation.