What is the role of emulsifiers?

• A. Promote mixing of immiscible liquids
• B. Act as antioxidants
• C. Increase viscosity
• D. Provide fragrance

Answer: (A)

Emulsifiers act at the oil–water interface to lower interfacial tension and form a stabilizing film around droplets, enabling mixing of immiscible liquids and preventing droplets from coalescing. They are amphiphilic, with a polar head that loves water and a nonpolar tail that loves oil, so they line up at the boundary and reduce the energy needed to create and maintain dispersed droplets. In pharmaceutical emulsions, this allows stable oil-in-water or water-in-oil systems when you need to disperse one liquid within another. The other options describe different roles—antioxidants prevent oxidation, fragrances provide scent, and viscosity modifiers alter flow properties—not the primary action of enabling mixing and stabilizing immiscible liquids.