Ionic liquid microcapsules for the topical delivery of pterostilbene: Enhanced transdermal delivery and anti-wrinkle and skin brightening effects

Pterostilbene (PTB) is a hydrophobic compound derived from plants in the Astragalus family. PTB possesses remarkable skin brightening and antioxidant properties. However, delivery methods for PTB require enhancement, and this can be achieved by formulating suitable carriers. In this study, we prepared ionic liquid microcapsules containing PTB by using a microencapsulation technique based on a matrine and cocinic acid ([Mat][Coc]) ionic liquid. The particle size of the microcapsules was 154.5 ± 3.42 nm, and the encapsulation efficiency was as high as 99.7 %. Further, the PTB-loaded ionic liquid microcapsules had good biocompatibility, enhanced skin retention (7.7-times higher than that of free PTB), and improved skin penetration without damaging the skin structure. Clinical testing with human subjects revealed that the microcapsule emulsion reduced fine lines and brightened skin tone. Therefore, PTB-loaded ionic liquid microcapsules have promise for use in cosmetic formulations and applications in transdermal drug delivery and efficacy enhancement.