Serum Formulation Feedback

Thank you for sharing your serum formulation! It's great that you are experimenting with creating your own products. Let's go through your questions and the formula.

Your formula appears to be designed as an emulsion, combining oil/silicone phase ingredients with water-soluble ingredients. The inclusion of an emulsifier or coupling agent is essential for successfully combining these phases into a stable serum.

Here is feedback on your questions:

1. Is this formula correct?
   The formula structure with separate oil/silicone and water phases is common for emulsions. The ingredients you've chosen target acne (Mangosteen, Pennywort) and potentially skin brightening (AHA). However, the success and stability of the final serum will heavily depend on the specific "Oil + Emulsifier" and "Silicone gel" products used, and importantly, the method of combining Phase A and Phase B.

2. Which ingredients in Phase A should be mixed first?
   In Phase A, you should first mix the oil/silicone components and the emulsifier/coupling agent. Then, add the oil-soluble extracts (AHA extract, Mangosteen extract) to this mixture and ensure they are fully dispersed or dissolved.

3. When Phase A is mixed, should the water part be mixed in gradually?
   Yes, absolutely. To form a stable emulsion, Phase B (the water phase) should be added gradually to Phase A (the oil/silicone phase containing the emulsifier) while continuously mixing. High-shear mixing is often recommended during the emulsification process to create small, stable droplets.

4. If the serum is too concentrated, can Cyclomethicone be added? And can Cyclomethicone be added after Phenoxyethanol is added?

   • Adding Cyclomethicone can help reduce the viscosity and provide a lighter feel to the serum. However, adding it after the emulsion is fully formed might destabilize the emulsion, especially if the emulsifier system is not robust enough to handle the additional oil phase ingredient. It's generally better to adjust the oil/silicone phase composition before the emulsification step.
   • Adding Cyclomethicone after Phenoxyethanol has been added is possible, but again, consider the potential impact on emulsion stability. Phenoxyethanol is a preservative and is typically added during the cool-down phase of an emulsion (below 40°C) or to the water phase before combining, as it is water-soluble. Adding Cyclomethicone, which is oil-soluble, after the preservative is in the water phase and the emulsion is formed might not distribute evenly and could potentially affect the preservative's efficacy or the serum's stability. It is best practice to finalize your base formulation and viscosity before adding the preservative.

Recommended Procedure:

1. Phase A: Combine the oil/silicone (Oil + Emulsifier, Cyclomethicone, Silicone gel, Silky Serum Base Plus) and mix well. Add the AHA extract and Mangosteen extract to Phase A and mix until dispersed/dissolved.
2. Phase B: Combine Water and Pennywort extract and mix well. Add Phenoxyethanol to Phase B and mix until dissolved.
3. Combine Phases: Slowly add Phase B to Phase A while mixing continuously. Use a high-shear mixer if possible to create a stable emulsion. Continue mixing until the serum is uniform.

Remember to check the compatibility and recommended usage rates for each specific ingredient you are using, as these can vary between suppliers.