European Journal of Biomedical and Pharmaceutical Sciences

MICROEMULSION: A NOVEL APPROACH FOR DRUG DELIVERY

Nidhi Gupta*, Mohd. Aqil Siddiqui, Arpita Singh, Swarnima Pandey, Nitish Kumar, Amresh Gupta

ABSTRACT

The dispersions of nanometer-sized droplets of an immiscible liquid within another liquid are known as Microemulsions. The addition of surfactants cosurfactants facilitated the Droplet formation. Nevertheless, the cosmetic researchers still try to understand and develop the most acceptable cosmetically eloquent and functional products possible. Aesthetically appealing products can be formulated as transparent o/w or w/o dispersions called microemulsions. ―A microemulsion is a system of water, oil and an amphiphile which is a single optically isotropic and thermodynamically stable liquid solution‖. Microemulsions are considered as small-scale versions of emulsions, i.e., droplet type dispersions either of water-in-oil (w/o) or of oil-in-water (o/w), having a size range in the order of 5−50 nm in drop radius. In particular, in emulsions the average drop size grows continuously with time so that phase separation ultimately occurs under gravitational force, i.e., they are thermodynamically unstable and their formation requires the input of work. The drops of the dispersed phase are generally large (> 0.1 μm) so that they often take on a milky, rather than a translucent appearance. Schulman et al were use The term ―microemulsion‖. in 1959 to describe a multiphase system consisting of water, oil, surfactant, and alcohol, which forms a transparent solution. There has been much debate about the word "microemulsion‖ to describe such systems. Although not systematically used today, some prefer the names ―micellar emulsion‖ or ―swollen micelles‖.

Keywords: Microemulsion, Surfactant, Co-surfactant, Phase diagram.