Evaluation of Your Physical Sunscreen Formula

Thank you for sharing the physical sunscreen formula you received. Based on the ingredients and percentages provided, this formula appears to be a well-structured starting point for a physical sunscreen aiming for SPF40 PA+++.

Here's a look at the key components:

• UV Filters: The formula uses a combination of 7.5% Titanium Dioxide Nano EasyDisperse and 15% Zinc Oxide 200nm EasyDisperse. These are standard physical UV filters. The "EasyDisperse" types (like Titanium Dioxide 200nm EasyDisperse and Zinc Oxide 200nm EasyDisperse) are treated to help them disperse better in silicone or oil phases, which is crucial for achieving even coverage and effective UV protection without excessive white cast. This combination of filters is appropriate for broad-spectrum UVA/UVB protection.
• Silicone Base: Ingredients like Cyclomethicone (specifically Cyclopentasiloxane) and Dimethicone (such as Dimethicone Light/50) form the continuous phase of this water-in-silicone emulsion. Silicones provide a smooth, non-greasy feel, help spread the UV filters evenly, and contribute to water resistance. Cyclopentasiloxane is a lightweight, volatile silicone that provides a silky feel and evaporates, while Dimethicone provides lasting slip and emollience.
• Emulsifier: SiliSolve (PEG-10 Dimethicone) is a silicone-compatible emulsifier designed to create stable water-in-silicone emulsions, allowing the water phase to be incorporated into the silicone/oil phase.
• Other Components: The formula includes water and a preservative, which are necessary for the emulsion's stability and microbial protection. The note about adjusting with "Powder cream" at the end suggests incorporating a powder ingredient, such as Sericite Powder (CompactPro™), to modify the final texture, potentially reducing greasiness or adding a soft-focus effect. Isopropyl Myristate is mentioned as an alternative emollient for Cyclomethicone, offering a different feel, with a caution about usage levels due to potential pore clogging.

Usability and Adjustments:

The formula is fundamentally sound for a physical sunscreen. The concentrations of the UV filters are within typical ranges for achieving high SPF. The mixing instructions (adding the water phase slowly to the silicone phase) are correct for forming a water-in-silicone emulsion.

Potential considerations or adjustments could include:

• Stability Testing: While the formula seems plausible, actual stability (preventing separation over time) and SPF/PA efficacy would need to be confirmed through testing.
• Texture: The suggested adjustments using Dimethicone, Cyclomethicone, Isopropyl Myristate, or a powder like Sericite Powder are good ways to fine-tune the feel on the skin (e.g., more or less spreadable, more or less powdery finish). You can experiment with these based on your preference.
• Preservation: Ensure the chosen preservative is effective in this specific emulsion type and at the recommended concentration.
• "Powder cream" Ingredient: If "Powder cream" refers to a specific blend, understanding its composition will help predict its effect on the final texture. If it refers to a general powder, using cosmetic powders like Sericite Powder or Mica Powder is common for texture modification in such formulas.

Overall, the physical sunscreen formula you received appears to be a valid formulation approach.

Regarding the "organic sunscreen" formula you are still waiting for, the staff's suggestion of SPF Protect Ultra™ II points towards a chemical sunscreen formulation, as "organic" in this context often refers to carbon-based chemical UV filters. They also suggested considering a physical sunscreen option using a liquid form of Titanium Dioxide (like Titanium Dioxide 15nm Liquid), which is another way to incorporate physical filters compared to the powder forms in your current formula.

It is advisable to follow up regarding the second formula you paid for.