Choosing an emulsifier for an oil-based dosage form

An emulsifier is not chosen by name alone. The same grade can perform well in an emulsifiable concentrate and fail in an oil dispersion, because the two systems ask different things of it.

Start with the carrier

Methyl oleate, aromatic solvents and vegetable oils have different solvency and different interfacial behaviour. An emulsifier that gives a spontaneous bloom in one carrier may leave a scum ring in another.

Then the water

Dilution water varies in hardness and electrolyte content. A pair that produces a stable emulsion in distilled water can cream within minutes in hard field water.

Then the dosage form

An EC needs a pair that forms an emulsion on dilution. An OD adds a solid phase and needs dispersant and rheology support as well. An EW starts as an emulsion and must survive storage. An ME must stay clear and thermodynamically stable.

Our current emulsifier range covers oil emulsifiers for vegetable-oil and methyl-oleate systems, a propanil-formulation emulsifier and an anionic emulsifier for organophosphate formulations. Tell us the carrier, the active ingredient and the water you dilute in, and we will point you at the closest starting point.