Review of Hybrid Sunscreen Formulation

Thank you for sharing your Hybrid Sunscreen formulation and question. Let's review the formula and address your question about adding Cyclomethicone.

Your formula consists of:

• Water (63%)
• SPF Protect Ultra (20%)
• Amino Silk (3%)
• Matte Silica (3%)
• Silky Serum Base Plus (10%)
• Preservative (1%)

Total: 100%

The mixing steps you described are appropriate for incorporating the ingredients.

Regarding your question about adding Cyclomethicone if the formula is too thick:

You can certainly add Cyclomethicone to the formula. It is a lightweight silicone fluid that evaporates quickly and is known for providing a silky, non-greasy feel and improving the spreadability of cosmetic products. It is often used to enhance the texture and application of creams and serums.

However, as noted in the previous reply, adding Cyclomethicone may not significantly reduce the overall thickness of the formula. Its primary function is to improve the skin feel and spread, not to act as a strong thinning agent for a formula with a high solid/powder content.

The thickness you are experiencing is likely due to the combination of factors in your formula, particularly the powder load and the base:

• High Powder Content: Your formula includes 20% SPF Protect Ultra, 3% Amino Silk, and 3% Matte Silica, totaling 26% powder/solid ingredients (assuming SPF Protect Ultra is a powder or contains a significant amount of dispersed solids, and Amino Silk and Matte Silica are powders). A high concentration of powders can significantly increase the viscosity and thickness of a formulation.
• Amino Silk and Matte Silica: While these ingredients are excellent for improving skin feel, absorbing oil, and providing a matte finish, using them at a combined 6% is quite a high level. As mentioned in the previous reply, high levels of these powders can contribute to thickness and potentially lead to issues like a white cast or pilling on the skin.
• Silky Serum Base Plus: This base also contributes to the texture and viscosity of the final product, influenced by the water and oil ratios.

Recommendations:

1. To reduce thickness: The most effective way to reduce the thickness of this formula would be to decrease the total percentage of the powder ingredients, specifically Amino Silk and Matte Silica. You might try reducing their combined percentage to 2-4% in future batches to see if that improves the texture while still providing the desired feel and oil absorption.
2. Adding Cyclomethicone: If you wish to improve the skin feel, making it silkier and easier to spread, you can add Cyclomethicone. Start with a small percentage (e.g., 1-5%) and add it in the final step, ensuring it is fully mixed. While it might slightly affect viscosity, its main benefit here will be textural.

In summary, while you can add Cyclomethicone, focus on adjusting the powder percentages (Amino Silk and Matte Silica) if your primary goal is to reduce the formula's thickness.