Design of Decanoic Acid/Polysorbate 80 Composite Vesicles as Cosmetics Carrier: Stability, Skin Permeability, Antioxidant and Antibacterial Activity

Fatty acid vesicles are natural biomaterials which possess unique bilayer structures and offer biomimetic advantages for drug and gene delivery. Nevertheless, the formation of fatty acid vesicles is limited to neutral alkaline circumstances and cannot adapt to the acidic environment of the living system. In this work, the non-ionic surfactant polysorbate 80 (TW80) was introduced, extending the pH window of vesicles formed by decanoic acid (DA) from 6.90-7.80 to 2.28-6.31. The DA/TW80 composite vesicles were used to encapsulate quercetin (QT), achieving an encapsulation efficiency of up to 75.6%. The formation of DA/TW80/QT composite vesicles was confirmed through Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction. Moreover, free QT was released rapidly, while QT encapsulated in the DA/TW80 composite vesicles demonstrated a slower release profile. Skin permeability studies revealed that the cumulative drug penetration within 24 h using the DA/TW80/QT composite vesicles reached approximately 904.7 μg·cm-2, 1.81 times higher than that of a QT solution. Furthermore, the DA/TW80/QT composite vesicles demonstrated enhanced antioxidant activity and greater antibacterial efficacy compared to either the drug or the vesicles alone. The results provide a crucial foundation for the application of drug-loaded vesicles in cosmetics.