Formulation Compatibility for Oil and Silicone in Water

Question

I need advice regarding a formulation I'm trying to create. The formula must contain the following components: ISP (Isopropyl Palmitate) at 8%, Silicone Oil at 5%, Cocamidopropyl Betaine at 1%, and the rest is water. I would like to ask for recommendations on the steps or procedure needed to make all these ingredients compatible and mix together. Do I need to add any intermediary substances or co-solvents to help with mixing (such as Magnesium Sulfate)? Thank you for your answer.

MySkinRecipes Expert · Accepted Answer

Formulation Compatibility Advice

Based on the components you've listed:

ISP (Isopropyl Palmitate) and Silicone Oil are oil-soluble ingredients.
Water is the aqueous phase.
Cocamidopropyl Betaine is a surfactant that dissolves in water.

Oil-based ingredients like Isopropyl Palmitate and Silicone Oil do not naturally mix and stay dispersed in water. To create a stable, homogenous mixture (like an emulsion), you need an ingredient that can bridge the oil and water phases.

At 1% concentration, Cocamidopropyl Betaine is primarily used as a co-surfactant or foam booster in cleansing products. It is generally not sufficient on its own to emulsify 8% Isopropyl Palmitate and 5% Silicone Oil into a stable mixture in water.

You also asked about using Magnesium Sulfate. Magnesium Sulfate is typically used as an emulsion stabilizer in water-in-oil formulations, where water droplets are dispersed in an oil phase. Your formulation, with a large percentage of water, is an oil-in-water system (oil dispersed in water). Therefore, Magnesium Sulfate is not suitable for stabilizing this type of mixture and will not help make your ingredients compatible.

To make your formulation compatible and stable, you would need to incorporate a suitable emulsifier or a more robust surfactant system specifically designed to emulsify oils and silicones into water. The specific type and amount of emulsifier needed would depend on the exact types of Silicone Oil and Isopropyl Palmitate you are using, as well as the desired final texture and stability.

The mixing procedure would depend on the chosen emulsifier, but generally involves:

Mixing the oil-soluble ingredients (Isopropyl Palmitate, Silicone Oil, and the emulsifier if it's oil-soluble) together in one phase.
Mixing the water-soluble ingredients (Cocamidopropyl Betaine and water, plus any water-soluble emulsifier) together in another phase.
Gradually adding one phase to the other while mixing, often with high shear, and sometimes with heating depending on the emulsifier requirements.

Without a proper emulsifier, your mixture will likely separate into distinct oil and water layers over time.