Effect of Liposomal Fluidity on Skin Permeation of Sodium Fluorescein Entrapped in Liposomes

The study investigated the effect of liposomal fluidity on the skin permeation of sodium fluorescein (NaFl) using ultradeformable liposomes (ULs) with terpenes as penetration enhancers. It was found that ULs with terpenes significantly enhanced NaFl penetration through the skin, primarily via the transfollicular pathway, bypassing the stratum corneum. The incorporation of terpenes and Tween 20 increased vesicle fluidity, which played a crucial role in enhancing follicular penetration, thereby improving the transdermal delivery of NaFl. Confocal laser scanning microscopy (CLSM) confirmed that ULs and ULs with terpenes penetrated the skin through both follicular and nonfollicular regions, with ULs containing 1% cineole showing the deepest penetration.