Nanoparticle coated emulsions as novel dermal delivery vehicles

The dermal delivery characteristics of hydrophilic silica nanoparticle coated medium chain triglyceride oil-in-water emulsions are reported and correlated with the physicochemical and interfacial properties of the emulsion based drug carriers. The synergistic drug/stabiliser/nanoparticle interactions are demonstrated to be a function of the charge and concentration of the initial emulsion stabiliser; charge and initial loading phase of nanoparticles and physicochemical properties of the drug molecule. The improved physical stability of the emulsions and the chemical stability of two model lipophilic agents (all-trans-retinol and acridine orange 10-nonyl bromide) confirm that engineered nanoparticle layers can enhance the shelf-life of liable lipophilic agents. Nanoparticle coatings are shown to control the in-vitro release of active agents from emulsions and significantly promote skin retention. The lipophilic agents distributed into the deeper viable skin layers without permeation through full-thickness skin and hence systemic exposure. Nanoparticle-coated submicron oil-in-water emulsions can serve as novel dermal carriers with controlled release kinetics and targeted drug delivery.