Penetration Process of a Hydrated Deep Eutectic Solvent Through the Stratum Corneum and its Application as a Protein Penetration Enhancer

• Main Authors: Dr. Mina Sakuragi, Emika Maeda, Prof. Katsuki Kusakabe
• Format: Article
• Language: English
• Published: Wiley-VCH 2020-09-01
• Series: ChemistryOpen
• Subjects: deep eutectic solvents; drug delivery; stratum corneum; lysozyme; X-ray diffraction
• Online Access: https://doi.org/10.1002/open.202000114

Abstract The penetration mechanism of choline chloride‐glycerol deep eutectic solvent (DES) through the stratum corneum (SC) as a potential solvent for a novel enhancer of protein penetration into the skin was investigated in a wide and small angle X‐ray diffraction study. We found that DES penetrated through intercellular lipids but not the corneocytes. DES seemed to extract a portion of lipids of the short lamellae in the SC. Hydrated DES with a DES to water weight ratio of 9 to 1 (9DES‐1H2O) showed the strongest interaction with the lipids in the SC compared with water, DES, and hydrated DESs with another weight ratio of DES to water (DES : water=8 : 2). In a skin penetration test with a fluorescently labelled lysozyme, 9DES‐1H2O increased the amount of penetration through the SC by two‐fold compared with HEPES buffer.