Emulsion in Water (EW)
EW (Emulsion in Water) formulations are stable emulsions in which a water‑insoluble liquid is dispersed within a continuous aqueous phase. This water‑insoluble liquid may be a liquid active ingredient or a solid active ingredient that has been dissolved in a suitable solvent.
Compared with EC (Emulsifiable Concentrate) formulations, EW formulations are considered a safer and more environmentally friendly option because water is used as the continuous phase instead of organic solvents. This reduces phytotoxicity, minimizes fire and explosion hazards, simplifies handling, and lowers the environmental impact.
EW – an optimal choice thanks to its key advantages
Despite its advantages, EW formulations still have certain limitations
Key principles for developing an EW formulation
To formulate an effective and stable EW (Emulsion in Water) product, the following sequence of steps must be followed. First, if the active ingredient is in solid form, an appropriate solvent must be identified to dissolve it. Next, suitable surfactants are selected according to the formulation requirements. Antifreeze agents and thickeners are then incorporated, followed by the addition of water, preservatives, and defoamers. This mixture is stirred until a uniform, continuous aqueous phase is obtained.
In a separate step, emulsifiers are combined with the active ingredient or oil phase and mixed until a homogeneous dispersed oil phase is formed. This oil phase is then slowly added to the aqueous phase under gentle agitation. Finally, high‑shear mixing is applied to fully homogenize the emulsion system.
The main components commonly included in an EW formulation are:















