Background: In recent years, colloidal delivery systems based on nano-emulsion are gaining
popularity; being used for encapsulation and delivery of many drugs. This review therefore aims at summarizing
various methods of nano-emulsion formulation and their use as a topical and transdermal delivery
vehicle for a number of active pharmaceutical ingredients from different pharmacological classes.
Methods: This article represents a systematic review of nano-emulsions for topical and transdermal
drug delivery. A vast literature was searched and critically analysed.
Results: Nano-emulsions are thermokinetically stable dispersion systems, which have been used in topical
and transdermal delivery of a number of pharmaceutically active compounds. Nano-emulsions have a narrow
droplet size range with tuneable surface properties, which make them an ideal delivery vehicle. Nanoemulsions
have a number of advantages over conventional emulsions, including easy preparation using
various low and high energy methods, optical transparency, high solubilisation capacity, high stability to
droplet aggregation and the ability to penetrate the skin; thus allowing the transdermal delivery of drugs.
Conclusion: This review indicated that nano-emulsions are promising vehicle for entrapping various
drugs and are suitable for traversing the skin barrier for systemic effects.