title: Traversing the Skin Barrier with Nano-emulsions.
abstract: 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.
  
  
  CONCLUSIONS
  This review indicated that nano-emulsions are promising vehicle for entrapping various drugs and are suitable for traversing the skin barrier for systemic effects.
authors.affiliation: Centre of Excellence for Pharmaceutical Sciences, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa.
authors.forename: Cornel
authors.initials: C
authors.lastname: Burger
authors.affiliation: Faculty of Pharmacy, University of Central Punjab, Lahore 54000, Pakistan.
authors.forename: Yasser
authors.initials: Y
authors.lastname: Shahzad
authors.affiliation: Centre of Excellence for Pharmaceutical Sciences, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa.
authors.forename: Alicia
authors.initials: A
authors.lastname: Brummer
authors.affiliation: Centre of Excellence for Pharmaceutical Sciences, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa.
authors.forename: Minja
authors.initials: M
authors.lastname: Gerber
authors.affiliation: Centre of Excellence for Pharmaceutical Sciences, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa.
authors.forename: Jeanetta
authors.initials: J
authors.lastname: du Plessis
mesh_terms: D000279:Administration, Cutaneous; D002626:Chemistry, Pharmaceutical; D004655:Emulsions; D006801:Humans; D053758:Nanoparticles; D012867:Skin / Q000187:drug effects*; D012869:Skin Absorption
chemical_list: D004655:Emulsions
keywords: Emulsification; micro-emulsions; nano-emulsions; skin permeation; topical drug delivery; transdermal drug delivery