Intercellular lipid-cored, hectorite nanoplatelet-armored pickering emulsions with enhanced transdermal delivery and epidermal hydration†

This study presents intercellular lipid-based Pickering emulsions (ILPEs) comprising a core of intercellular lipids (ILs) and an exterior solid layer of hectorite nanoplatelets (HNPs), formulated via an oil-in-water (O/W) Pickering emulsion technique to augment dermal penetration and moisture retention. Cationic surfactant-modified HNPs electrostatically interacted with stearic acid and ILs, forming robust, organized lamellar structures at the O/W interface and within the core. HNP integration into the IL matrix significantly elevated the interfacial modulus, enhancing emulsion stability. HNP- and SA-modified ILPEs demonstrated uniform distribution of a proxy drug across porcine epidermis to a depth of 20 μm, maintaining approximately 50% hydration after 72 h. These findings underscore the potential of ILPEs for cutaneous applications, offering superior stability, epidermal penetration, and improved stratum corneum hydration.