Silicone-Free Sunscreen Formulation and Mixing Method

Yes, the silicone-free sunscreen formulation you provided is possible, and the percentages add up correctly to 100%. Regarding your mixing method, the general approach of heating both the water and oil phases and then combining them to form an emulsion is correct. However, there is a point to consider regarding Ectoin.

Ectoin can potentially be degraded by high heat. Heating it to 70°C along with the entire water phase may not be ideal. It is recommended to add Ectoin during the cool-down phase, after the emulsion has cooled down (below 40°C).

Regarding whether heating is necessary, heating both phases to around 70°C is a standard method for creating stable emulsions. It helps the emulsifier (Milk Lotion Maker™) work effectively and ensures that the physical sunscreen ingredients (Titanium Dioxide and Zinc Oxide) are well dispersed in the cream, contributing to the stability of the final product. Therefore, heating is still necessary for this formulation, but you should adjust the step for adding Ectoin.

Recommended Mixing Method:

1. Prepare the Water Phase: Combine Water and Mild Preserved Eco. Heat to approximately 70°C.
2. Prepare the Oil Phase: Combine Titanium Dioxide 15nm Liquid, Zinc Oxide 35nm Liquid, and Milk Lotion Maker™. Heat to approximately 70°C.
3. Combine Phases: Slowly add the oil phase into the water phase while stirring continuously (e.g., with a high-shear mixer or stick blender) until a homogeneous emulsion forms.
4. Cool Down: Continue stirring while the emulsion cools.
5. Add Ectoin: When the temperature drops below 40°C, add Ectoin and stir until fully incorporated.
6. Check pH: (Optional step for completeness) Check the pH of the cream and adjust it to a skin-friendly range (generally around 5.5-6.5) if necessary.

This formulation is possible and is a good option for those who wish to avoid a silicone base.