NANO-EMULSION-ANOVERVIEW FRAMEWORKS

Nano-emulsions are colloidal drug delivery systems made up of oil and water phases stabilized by suitable surfactants, with droplet sizes usually between 20 and 200 nm. Because of their small size, nano-emulsions have special physicochemical properties like high surface area, optical clarity, better kinetic stability, and improved ability to dissolve drugs.[1] These systems have attracted a lot of interest in pharmaceutical, cosmetic, and food industries, especially for delivering drugs that do not dissolve well in water. Nano-emulsions can be classified as oil-in-water, water-in-oil, or multiple emulsions, depending on the types of dispersed and continuous phases. Their performance mainly depends on key factors like droplet size distribution, zeta potential, interfacial tension, viscosity, pH, and stability in varying conditions. Several high-energy methods, such as high-pressure homogenization, ultrasonication, and micro fluidization, along with low-energy methods like phase inversion temperature, phase inversion composition, and spontaneous emulsification, are used to create them. Despite their benefits, such as better bioavailability, improved patient compliance, and flexibility in dosage forms, nanoemulsions also have challenges. These include thermodynamic instability, high surfactant needs, and difficulties in scaling up production.[2] Still, their broad applications in oral, topical, ocular, parenteral, and targeted drug delivery systems highlight their great potential. This overview focuses on the basic elements, preparation methods, physicochemical traits, benefits, drawbacks, and various uses of nano-emulsions as promising carriers in modern drug delivery.[3]