In Vitro Percutaneous Absorption of Pine Bark Extract (Pycnogenol) in Human Skin

One promising class of antioxidant compounds is polyphenols, contained abundantly in pine bark extract (Pycnogenol®—pine bark extract). This medicinal extract is utilized for its anti‐inflammatory properties. Its pharmacological action in skin depends on the kinetics of its absorption. In this study the dermal bioavailability of pine bark extract was investigated. Viable human skin, adapted on continuously perfused Franz cells, was applied with 5% (w/v) pine bark solution. Samples were taken at 0.5, 1, 2, 4, 6, 8, 10, and 12‐hour intervals and analyzed for detection of pine bark extract constituents by high performance liquid chromatography (HPLC) (reversed phase column, isocratic conditions) coupled with an electrochemical detector (EC). Several constituents of pine bark extract such as gallic acid, protocatechuic acid, catechin, p‐hydroxybenzoic acid, vanillin, and one unidentified constituent were detected. These findings indicate that pine bark extract is readily absorbed by human skin and can be used for topical application.