Formulation Issue: White Particles and Uneven Texture in Silicone/SPF Cream

Question

I am making a cream/lotion with the following formula:

Distilled Water: 64.00%
SPF Protect Ultra™: 20.00%
Cyclomethicone / Cyclopentasiloxane: 7.00%
Silicone Gel Base (Ultra Clear): 6.00%
Light Cream Maker: 2.00%
Phenoxyethanol: 1.00%

My steps were:

Weighed the water first.
Dissolved Silicone Gel Base (Ultra Clear) in Cyclomethicone / Cyclopentasiloxane separately.
Mixed SPF Protect Ultra™ with Light Cream Maker and stirred until combined. Then added the mixture from step 2 and stirred. I observed small particles starting to form. I continued stirring until they seemed combined, and then gradually added water little by little.

After mixing, the cream turned yellowish, but it doesn't seem well combined. There are small white fibrous particles dispersed throughout the texture, and some areas look like they haven't mixed well with the water. What is causing this? Did I mix in the wrong order, or was the mixing insufficient? Should I have added Silisolve? The resulting texture is light and smooth, and it feels reasonably waterproof.

MySkinRecipes Expert · Accepted Answer

Formulation Issue Analysis

The issue you are experiencing with your formulation, resulting in small white particles and an uneven texture, is likely due to the high percentage of the oil and silicone phase in your recipe exceeding the capacity of the Light Cream Maker.

Based on the product information for Light Cream Maker, it is designed to emulsify formulas with an oil phase of up to 20%. Additionally, when used with silicones like Cyclomethicone, the total silicone content should not exceed 10% of the formula.

Your formula contains approximately 33% oil/silicone phase (20% SPF Protect Ultra™ + 7% Cyclomethicone + 6% Silicone Gel Base) and 13% silicone (7% Cyclomethicone + 6% Silicone Gel Base). This significantly exceeds the recommended limits for Light Cream Maker, which can lead to the emulsifier being unable to properly bind the oil/silicone phase with the water phase, resulting in instability, separation, and the appearance of particles or uneven texture.

Insufficient mixing could also contribute to this issue, as proper blending is crucial for the Light Cream Maker to create a smooth emulsion.

Regarding the addition of Silisolve, this ingredient is not included in your current formula, and the primary issue appears to be related to the emulsifying capacity of Light Cream Maker with your high oil/silicone load.

To resolve this, you may need to:

Adjust your formula to reduce the total percentage of the oil and silicone phase to be within the recommended limits of Light Cream Maker (ideally <= 20% total oil, <= 10% silicone).
Consider using a different emulsifier system that is specifically designed to handle higher oil and silicone concentrations.

The yellow color you observed is likely from the SPF Protect Ultra™, which is described as a light yellow oil.