Lipid materials for topical and transdermal delivery of nanoemulsions

Over the past two decades, nanoemulsions have gained significant scientific attention because of their unique features such as high solubilization capacity, spontaneous formation, enhanced thermodynamic stability, ability to load both hydrophilic and hydrophobic drug molecules, enhanced stability of the encapsulated therapeutic molecule, and high diffusion/absorption rates. Further, they have applications in dermal and epidermal targeting for various skin disorders. The materials used in nanoemulsion formulations can greatly influence the in vitro and in vivo performance of the therapeutic moiety. This review describes various lipid materials used in the preparation of nanoemulsions for topical and transdermal drug delivery. The lipids are classified as vegetable oils, fatty acids, fatty alcohols, medium chain glycerides, and fatty acid esters.