Sunscreen Formulation Questions: Ingredient Color and Thickener Suitability

Question

Based on the following sunscreen formula: 1. Water 44%, 2. Titanium Dioxide 15nm Liquid 25%, 3. Cyclomethicone 15%, 4. Zinc Oxide 35nm Liquid 15%, 5. Mild Preserved Eco 1%. I have the following questions: 1. Is Titanium Dioxide 15nm Liquid white or clear? 2. Is Zinc Oxide 35nm Liquid 15% white or clear? 3. Is it necessary to add Xanthan Gum and Propylene Glycol to this formula? If yes, at which step should they be added? Can Aristoflex AVC be used instead?

MySkinRecipes Expert · Accepted Answer

Sunscreen Formulation Questions

Here is the information regarding your sunscreen formulation questions:

Based on the product descriptions:

Titanium Dioxide 15nm Liquid (Gloss) has a white liquid appearance.
Zinc Oxide 35nm Liquid has a white liquid appearance.
Regarding the addition of Xanthan Gum and Propylene Glycol, and the possibility of using Aristoflex AVC:
- Your formula is a water-in-oil (W/O) emulsion, as indicated by the mixing procedure where water is added to the oil/silicone phase.
- Xanthan Gum is a water-soluble thickener primarily used in the water phase of oil-in-water (O/W) emulsions or in water gels. It is not suitable for thickening the internal water phase of a W/O emulsion and is not necessary for this formula structure.
- Propylene Glycol is a humectant and solvent that is soluble in water. While it can be added to the water phase of a formula, it is not essential for the structure or stability of this W/O emulsion. It is not necessary unless you specifically want its humectant properties.
- Aristoflex AVC is also a water-soluble gel-forming agent and emulsifier typically used to create O/W emulsions or water gels. It is not suitable for creating or stabilizing a W/O emulsion like your formula.

Therefore, Xanthan Gum, Propylene Glycol, and Aristoflex AVC are generally not necessary or suitable for this specific water-in-oil sunscreen formulation.