MICROEMULSIONS: CURRENT TRENDS IN SUSTAINED RELEASEDRUG DELIVERY SYSTEMS

Abstract

Microemulsions are one of the best candidates as sustained drug delivery system because of their long shelf life, improved drug solubilization with ease of preparation and administration. A microemulsion is considered to be a thermodynamically or kinetically stable liquid dispersion of oil and a water phases, in combination with a surfactant. The dispersed phase typically comprises small particles or droplets, with a size range of 5 nm-200 nm and has very low oil/water interfacial tension. Because the droplet size is less than 25% of the wavelength of visible light, microemulsions are transparent. These are formed readily and sometimes spontaneously, generally without high-energy input. In many cases a co-surfactant or co-solvent is used in addition to the surfactant, the oil phase and the water phase. The main objective of this review paper is to discuss microemulsions asdrug carrier system with other possible applications.