Adjusting Sunscreen Formula for SPF 45/PA+++

Based on your formula and the test results, the high SPF value (100-130) is primarily due to the high concentrations of Titanium Dioxide (25%) and Zinc Oxide (20%), which are the main UV filters. Other ingredients like BB Micro Silk and SoftGlow can also contribute to the SPF/PA value by scattering light or improving the dispersion and film-forming properties of the UV filters.

To reduce the SPF to your target of 45/PA+++, you need to decrease the concentration of the ingredients that contribute to the SPF. The staff recommended reducing Titanium Dioxide, Zinc Oxide, SoftGlow, and SiliSolve Plus.

You mentioned you prefer not to reduce BB Micro Silk, Softglow, and Pearl Red Mica. While BB Micro Silk and Pearl Red Mica can likely be kept at their current percentages, the staff specifically recommended reducing SoftGlow as it contributes to the SPF value and is one of the ingredients to adjust.

Therefore, the main ingredients to reduce are:

• Titanium Dioxide 15nm Liquid
• Zinc Oxide 35nm Liquid

Also, consider reducing SoftGlow as recommended by the staff. Reducing SiliSolve Plus (from 3% to 1.5-2.0%) is also recommended by the staff for formula stability, which may indirectly affect SPF consistency.

Finding the exact percentages to achieve SPF 45/PA+++ will require further experimental adjustments and re-testing of the formula.