In a water-in-oil (W/O) emulsion, the continuous phase is oil.

• A. True
• B. False
• C. Depends on formulation
• D. Water is continuous

Answer: (A)

In this context, continuous phase means the medium that surrounds and flows around the dispersed droplets. In a water-in-oil system, water droplets are dispersed inside an oil phase, so the oil forms the continuous matrix and water is the dispersed phase. That’s why the statement is true. This arrangement also guides formulation choices—stabilizing W/O emulsions typically uses lipophilic surfactants with low HLB values to keep the oil phase continuous. The structure influences properties like viscosity and drug release, since hydrophilic substances reside in the water droplets and must diffuse through the surrounding oil to be released. If the system were oil-in-water, the roles would be reversed with water as the continuous phase.