External phase:

The suspending vehicle chosen also governs the selection of the suspending agents to be employed. For example, in the case of non-polar liquids, such as aliphatic or halogenated hydrocarbons, fatty esters and oils, the best suspending agents are low HLB surfactants, water insoluble resins, and water-insoluble film formers. Polar liquids such as water, alcohols, polyols and glycols the higher HLB surfactants, clays silicates, gums and cellulose derivatives are usually preferred. Liquid vehicles are selected based on safety, density, viscosity, taste and stability considerations.