Insights into the Approach, Fabrication, Application, and Lacunae of Nanoemulsions in Drug Delivery Systems.

Many of the recently approved drug molecules that are therapeutically successful are found to be incompatible for the development of a novel delivery system and to take part in various health care management. Regardless of having better therapeutic properties, these molecules are barred from their effective clinical uses. The main reason attributed to it is poor solubility and/or poor permeability of drugs which finally emerges the drug to be low bioavailable. Nanoemulsions are one of the most acceptable nanolipoidal drug delivery system and appears to be a hope for the delivery of many of the Biopharmaceutical Classification System (BCS) class II and IV drugs. A nanoemulsion is a thermodynamically unstable isotropic mixture of oil, surfactant, and co-surfactants and is biphasic in nature. It can be either water in oil or oil in water and droplets are found in the range of 5 to 500 nm. The manufacturing and fabrication of nanoemulsions involve various natural, synthetic and semi synthetic materials using either low or high-energy methods. Application of nanoemulsions as a novel drug delivery system through several routes, especially oral, transdermal, ophthalmic, and intranasal, have been increased for various pharmacological aspects such as cardiovascular, anticancer, antimicrobial, and ophthalmic due to their stability, high solubilization capacity, and ease of preparation. The objective of this review is to focus on the aspects of manufacturing, fabrication, application, and some toxicological concerns related to nanoemulsions.