Highly efficient transdermal delivery of rutin via microemulsions containing deep eutectic solvents composed of choline chloride-polyethylene glycol

Abstract Microemulsions (MEs) incorporating a hydrated deep eutectic solvent (hydrated DES) were prepared in the inner phase. These MEs increase the rutin solubility and skin permeability. Conventional water-in-oil (W/O) MEs maintained a spherical structure during stratum corneum (SC) penetration. Conversely, MEs containing hydrated DES transitioned from an ellipsoidal to a spherical shape after applying SC. The released DES disrupts the lipid layers in the SC, enhancing the skin permeation of MEs containing DESs compared with W/O ME.