Effects and mechanisms of atomization on the transdermal delivery behavior of active ingredients with diverse properties

This study systematically examined the effects of atomization as a transdermal permeation enhancer on the transdermal delivery of active ingredients with different physicochemical properties and investigated the underlying mechanisms. Porcine ear skin served as an in vitro model, and skin permeation experiments were conducted using Franz diffusion cells. Receptor fluids were collected at specific time points, and samples of the stratum corneum and viable epidermis–dermis were separated and prepared. Quantitative and visualization methods, including high-performance liquid chromatography, fluorescence derivatization, and confocal laser scanning microscopy, were used to compare skin retention and transdermal permeation of adenosine (AD), tranexamic acid (TXA), calcein (CAL), and tocopheryl acetate (TA) under atomized and non-atomized conditions. Additionally, transepidermal water loss (TEWL) measurements and attenuated total reflectance–Fourier transform infrared spectroscopy (ATR-FTIR) were employed to analyze the mechanism behind the penetration enhancement caused by atomization. The findings showed that atomization increased skin retention within the stratum corneum and viable epidermis–dermis, as well as the transdermal permeation of all four active ingredients to varying degrees. The most significant enhancement was observed for TXA, which has a relatively low molecular weight and moderate lipophilicity, while the enhancement effects for highly hydrophilic AD and highly lipophilic TA were comparatively limited; however, atomization significantly increased the skin retention of TA. TEWL results indicated that skin permeability increased within 4 hours after atomization and largely recovered within 8 hours. ATR-FTIR analysis suggested that atomization may facilitate transdermal delivery by disrupting the lipid order and keratin conformation in the stratum corneum.This study provides theoretical support and experimental references for the advancement of atomization transdermal delivery technology, as well as the design and development of related atomization products.