This research focuses on deformable liposomes that have great potential as carriers of transdermal drug delivery. In this study, deformable liposomes are prepared using the natural surfactants polyglyceryl‐2 caprate and polyglyceryl‐10 stearate along with phosphatidylcholine and cholesterol to enhance skin penetration of taxifolin and taxifolin tetraoctanoate. Sizes of liposomes made with polyglyceryl‐2 caprate and polyglyceryl‐10 stearate are 64.70–91.30 and 90.20–110.70 nm, respectively. Then entrapment efficiencies and deformability indices are measured, respectively. Liposomes containing 30% surfactant have been selected because they have high entrapment efficiency, stability, and deformability. Crystallization and skin permeation are then measured. Crystallinity is compared using differential scanning calorimetry (DSC). Deformable liposomes containing 30% PGL‐2 caprate and carrying taxifolin tetraoctanoate (CDLTO3) have the lowest melting point (7.55 °C), equivalenting to its highest deformability index. The liposomes are observed by transmission electron microscopy (TEM). Skin permeation studies using Franz cells show that deformable liposomes increased drug permeation more than 1,3‐butylene glycol (1,3‐BG) and control liposomes without surfactant. In particular, when CDLTO3 is used, the amounts of taxifolin tetraoctanoate present in the stratum corneum and skin as well as the amount of permeation are greatest. In conclusion, deformable liposomes containing polyglyceryl‐2 caprate can be effective carriers for taxifolin, taxifolin tetraoctanoate. Practical Applications: Taxifolin is a flavonoid with antioxidative, antibacterial, anti‐inflammatory, and skin‐whitening properties. It would be useful in skin treatments and cosmetics if not for its poor stability. This study develops and characterizes a deformable liposome delivery method that can carry a taxifolin derivative with increased stability and provide better skin penetration compared to conventional liposome. The results can be applied to more effectively deliver beneficial drugs into the skin. Deformable liposomes using the natural surfactants polyglyceryl‐2 caprate and polyglyceryl‐10 stearate increase drug permeation more than did general liposomes. Taxifolin‐tetraoctanoate‐loaded deformable liposomes have the greatest skin permeation.

Chemically stable ester derivatives of taxifolin have become a focus of interest for their role in the satisfactory effects on human health. Accordingly, the aim of this study was to evaluate the physical and chemical stability of different formulations containing 0.02% taxifolin tetra-octanoate, which was proved to possess higher inhibitory effect on tyrosinase activity compared with taxifolin in a cell-free system. In the studies of physical stability, a Brookfield viscometer was used to determine rheological behavior of formulations containing taxifolin tetra-octanoate, and a portable pH meter was used to determine pH change. Moreover, chemical stability was determined by HPLC with UV detection. Formulations were evaluated for 12 weeks stored at 25 and 40°C. Results showed that storage time had no significant influence on viscosity of the formulations containing taxifolin tetra-octanoate, and pH value was relatively stable, which was within the limits of normal skin pH range. In the chemical stability studies, taxifolin tetra-octanoate in the essence formulation was most unstable at 40°C with about 81% degradation in 12 weeks of storage, however, the percentage of remaining taxifolin tetra-octanoate in cream formulation stored for 12 weeks at 25°C was the highest, about 93%. The results in this study may contribute to the development of more stable formulations containing taxifolin tetra-octanoate.