Microemulsion: A Versatile Vehicle for Drug Delivery

The term “Microemulsion” was first introduced by Hoar and Schulman (1943) to describe a clear solution obtained when normal O/W coarse emulsions were titrated with medium-chain length alcohols. Daniel son and Lind man (1981) define microemulsion as a system of water, oil, and amphiphile which is an optically isotropic and thermodynamically stable liquid solution. Microemulsion refers to a thermodynamically stable isotropically clear dispersion of two immiscible liquids, such as oil and water, stabilized by an interfacial film of surfactant molecules. A microemulsion is an oil phase and a water phase, 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. The microemulsion is 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.

Mr. Vibhu Jha, has completed M.S.Pharm.(Medicinal Chemistry) from NIPER Raebareli, U.P., India. He has pursued project work from CSIR-CDRI Lucknow, U.P. India. He has published 4 articles in reputed international journals and filed 2 patents. Currently, he is working as Assistant Professor in School of Pharmacy, ITM University, Gwalior, M.P. India.