ナトリウムヒアルロネート安定化ルテオリン負荷マイクロエマルションゲル：アトピー性皮膚炎に対する皮膚送達および治療効果を高めるための界面駆動型ナノキャリア

Luteolin (LUT), a promising phytochemical for atopic dermatitis (AD) therapy, is limited by poor solubility and skin permeability in topical application. To address this, a novel LUT-loaded microemulsion-based (LUT-ME) gel was developed to facilitate drug delivery. The optimal LUT-ME formulation, obtained by a pseudo-ternary phase diagram and D-optimal mixture design, comprised 7.23 % glycerol triacetate, 34.56 % Smix, and 58.21 % water. DLS analysis showed a mean droplet size of 28.77 ± 0.31 nm and a PDI of 0.31 ± 0.04, while the zeta potential was -2.95 ± 0.68 mV and the drug loading reached 7.28 ± 0.05 mg/mL. Characterization by TEM, XRD, and FTIR demonstrated uniform droplet morphology, amorphous LUT dispersion, and good drug-excipient chemical compatibility. Notably, LUT-ME more significantly suppressed reactive oxygen species (ROS) and pro-inflammatory mediators in LPS-stimulated RAW264.7 cells compared to free LUT. Incorporation of sodium hyaluronate (SH) yielded a shear-thinning gel with favorable spreadability, good stability, and negligible skin irritation. Moreover, enhanced skin permeation of LUT-ME gel (2.09-fold vs LUT gel) in ex vivo studies contributed to its superior anti-inflammatory and histopathological effects in an AD mouse model. These results indicate that LUT-ME gel markedly improves the topical therapeutic efficacy of LUT against AD.