Comparative study on ethosomes and transferosomes for enhancing skin permeability of sinapic acid

Sinapic acid (SA) is a phenolic compound having UV protective and antioxidant activities against skin diseases. However, its poor permeation across the skin restricts its therapeutic use. The studies suggest that the transferosomes and ethosomes improve the drug's permeability across the skin and facilitate the treatment of various skin diseases. Thus, the present study aimed to prepare vesicular nanoformulations such as transferosomes and ethosomes to improve the permeability of SA across the skin. The thin film hydration method was exploited to prepare sinapic acid-loaded transferosomes (SA-TRs) and sinapic acid-loaded ethosomes (SA-ETs). The particle size of SA-TRs and SA-ETs were 98.3 ± 0.5 nm and 108.5 ± 0.8 nm, respectively. Moreover, the prepared SA-TRs and SA-ETs were embedded into Carbopol 934 (1 % w/v) for ease of topical administration. The pH of vesicular-based hydrogels was in the range of 6.2–6.5, which is ideal for topical administration. The flow properties of vesicular-based hydrogels using a rheometer exhibited shear thinning behavior with the non-Newtonian flow, which is due to the colloidal structure of Carbopol aligned, wherein the polymer chain disarranged with increased shear stress. Further, the skin permeability study showed that SA-ETs hydrogel (66.5 ± 7.3 µg/cm2) exhibited higher permeability than SA-TRs hydrogel (53.2 ± 1.5 µg/cm2) and plain SA hydrogel (12.3 ± 1.4 µg/cm2). The mechanism behind permeation enhancement of SA using ethosomes was due to the flexibility of vesicles across the skin than plain SA hydrogel. Thus, upon comparison ethosomes-based approach could be a promising strategy to enhance the permeability of SA across the skin.