Sunscreen Formulation Questions

Based on the staff's response regarding your sunscreen formulation:

1. Mixing Instructions: Mix all liquid and gel ingredients together first and blend until homogeneous. Then, gradually add the powder ingredients and blend until fully incorporated.

2. Mixing without Heat: The staff recommends using heat during mixing. This is because heat helps the sunscreen ingredients disperse better within the formula, which is expected to improve their efficacy, even if you remove the Polyethylene Wax.

3. Necessity of SiliSolve: SiliSolve (or rather, SiliSolve Plus) is necessary for this formula. Although the liquid Titanium Dioxide and Zinc Oxide contain SiliSolve for their own dispersion during manufacturing, adding SiliSolve Plus to your overall formula helps ensure the sunscreen particles are well-dispersed throughout your final product for optimal sun protection. The staff specifically recommends using SiliSolve Plus (ID 680) instead of SiliSolve (ID 408) because your formula contains oil.

4. Adding Water: You can add water to the formula. Adding water will result in a creamier texture. If you do not add water, the texture will be more like a silky gel due to the high amount of Silicone Gel (ID 201). The staff did not specify the maximum amount of water or which ingredient to replace if adding water.

Regarding your follow-up question about WaterGuard Lite:

The staff's response suggests that the high amount of silicone in your original formula already provides sufficient water resistance by forming a film on the skin. Therefore, they believe that adding Polyethylene Wax (ID 1195) specifically for water resistance is not necessary. While the staff did not explicitly comment on replacing Polyethylene Wax with WaterGuard Lite (ID 287) or its compatibility with a silicone base, their overall point is that additional water-resistant additives might not be needed given the existing silicone content providing adequate water resistance.