Thermally Stable Nanoarchitectonics of Bicellar Nanocarriers for Superior Transdermal Delivery of <i>Centella asiatica</i> Extracts

This study systematically compares bicelles and liposomes as nanocarriers for the topical delivery of titrated extract of <i>Centella asiatica</i> (TECA), with a focus on their physicochemical properties, stability, and skin penetration efficiency. Compared to liposomes, bicelles exhibited significantly smaller particle sizes and superior colloidal stability across a broad temperature range, and demonstrated higher encapsulation efficiency. Ex vivo skin penetration studies using human cadaver skin confirmed that bicelles achieved deeper and more uniform skin penetration, which was primarily attributed to their nanoscale architecture rather than surface charge or hydrophobicity. These findings suggest that bicelles effectively overcome key limitations of conventional liposomes, such as insufficient delivery depth and thermal instability, offering significant advantages for the delivery and storage of hydrophobic ingredients in cosmetic applications. The high encapsulation efficiency enables effective loading of ingredients such as TECA, while the long-term stability across a broad temperature range supports their practical use in commercial formulations. The unique nanoarchitectonics and enhanced formulation stability position bicelles as promising alternatives to conventional liposomes for topical delivery. This work provides foundational insight into the nanoarchitectonic design of advanced lipid-based nanocarriers for effective transdermal delivery of bioactive compounds like TECA.