Why is the serum formulation white?

Based on the formulation you provided, the reason your serum turned out white is likely because it is an emulsion.

Here's a breakdown:

• Your formula contains Cyclopentasiloxane (8%), which is a silicone oil, and Polysorbate 20 (Tween 20) (2%), which acts as an emulsifier and solubilizer.
• When you mix oil-based ingredients (like Cyclopentasiloxane) with water using an emulsifier (like Polysorbate 20), you create an emulsion.
• Emulsions appear white or milky because light is scattered by the tiny droplets of the dispersed phase (in this case, the oil phase containing Cyclopentasiloxane) suspended within the continuous phase (the water).

This white appearance is a normal characteristic of many serum or lotion formulations that are emulsions. It doesn't necessarily mean there is a problem with the stability or effectiveness of your product, assuming the emulsion is well-formed and stable over time.

Your formula is essentially a complex system containing water-soluble actives (Niacinamide, Tranexamic Acid, Alpha Arbutin, Allantoin, Dipotassium Glycyrrhizate), a solvent (Butylene Glycol), a thickener (Xanthan Gum), a chelating agent (Disodium EDTA), an oil phase component (Cyclopentasiloxane), an emulsifier/solubilizer (Polysorbate 20), a preservative (Phenoxyethanol), and fragrance. The combination of the oil phase and the emulsifier is what gives it the white, emulsified appearance.

If you were aiming for a completely clear serum, you would need to reformulate significantly, likely by removing the Cyclopentasiloxane and Polysorbate 20 and ensuring all ingredients are water-soluble or can be incorporated into a clear water-based system using appropriate solubilizers (like Flora Solve Clear for the fragrance, if needed, instead of Polysorbate 20).

In summary, the white color is expected for this type of emulsified serum formulation.