Regarding Your Sunscreen Formula

Thank you for sharing your DIY sunscreen formula and questions. Let's address them:

1. Can this formula be mixed as written?
   The structure of your formula, particularly mixing water-soluble ingredients like Panthenol and Vitamin B3 into a silicone gel base (Silicone Gel Base Ultra Clear) and then combining this with an oil/silicone phase containing a high percentage of UV filters and emollients (45% oil/silicone phase + 1.5% Light Cream Maker), is unusual for a stable cream or lotion emulsion. Light Cream Maker is typically used for oil-in-water emulsions with a lower oil phase percentage (up to 20%). Combining a high oil/silicone load with a silicone gel base and water-soluble ingredients in this manner may lead to instability, separation, or a poor texture that doesn't properly disperse the UV filters for effective sun protection.

   It is generally recommended to follow a standard emulsion method for physical sunscreens, which involves creating a stable dispersion of the UV filters in an oil or silicone phase, preparing a separate water phase with water-soluble ingredients, and then combining them using an appropriate emulsifier system designed for high oil/UV filter loads and potentially silicones.

2. Does the formula make 100g?
   Yes, if the percentages listed are by weight, the total sum is 100%. So, if you measure each ingredient by weight according to the percentages, you will get a total of 100g of product.

3. Does this formula need a preservative?
   Yes, absolutely. Your formula contains water-soluble ingredients (Panthenol, Vitamin B3) and likely includes water (either added separately or present in some ingredients/implied by mixing water-soluble components). Any cosmetic formulation containing water requires a broad-spectrum preservative system to prevent the growth of bacteria, mold, and yeast, which can cause spoilage, instability, and potential skin infections. Since you mentioned you didn't purchase one, you will need to order a suitable cosmetic preservative before making this formula.

We recommend reviewing standard physical sunscreen formulation guides, such as the one previously linked by the staff, as they provide tested methods for creating stable and effective sunscreen products.