Pharmaceutical industry topical drug administration

In the pharmaceutical industry, the two most common routes of administration are via diet and gavage (PMA, 1988). Some compounds are given by drinking water, topical (dermal) application, or injection, depending on the expected clinical exposure route, which is the primary criterion for determining the route of administration in carcinogenicity studies. When more than one clinical route is anticipated for a drug, the dietary route is often chosen for practical reasons. 

Food and Drug Administration. 2010. ICH guidelines S9—Guidance for industry S9 non-clinical evaluation for anticancer pharmaceuticals. Available from http //www. fda.gov/downloads/Drugs/.../Guidances/ucm085389.pdf. Accessed November 10,2013 (ICH Topic S9 March 2010). 

The use of ttaditional disperse systems, e.g., macroemulsions, in the pharmaceutical industry has been limited due to manufacturing complexity and stability problems [117]. The characteristic properties of nano-emulsions (kinetic stability, small and controlled droplet size, etc.) make them interesting systems for pharmaceutical applications. Indeed, nano-emulsions are used as drug delivery systems for administration through various systemic routes. There are numerous publications on nano-emulsions as drug delivery systems for parenteral [17,18,28,29,118-124], oral [25,125-129], and topical administration, which includes the administration of formulations to the external surfaces of the body skin [32,130,131] and to the body cavities nasal [30,132] as weU as ocular administration [31,133-136]. Moreover, many patents concerning pharmaceutical applications of nano-emulsions have been registered [17,18,25,137-145]. An application of nano-emulsions in this field has been in the development of vaccines [33,146-147]. 

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