Adjusting Sunscreen Formula for SPF 50++

To achieve SPF 50 and improve the stability and texture of your sunscreen formula, I recommend several adjustments. The primary challenge in your original formula is the mix of water-dispersed ingredients in a high-silicone base, which can lead to instability or a gritty texture.

Key Adjustments:

1. Optimize Sunscreen Filters: To reach SPF 50, we need to increase the concentration of both chemical and physical filters. I have increased OMC to 10% and Zinc Oxide to 10%.
2. Switch Titanium Dioxide: Your original formula used a water-dispersed version. In a silicone gel base, it is much better to use Titanium Dioxide 250nm WaterProof™ (Dimethicone Treated). This ensures it stays in the silicone phase, providing a smoother application and better water resistance.
3. Stability (W/Si Emulsion): Since you are adding water-based actives (Hyaluronic Acid, Extracts), you must use SiliSolve Plus™ at a sufficient level (2-3%) to properly emulsify the water phase into the silicone phase.
4. SPF Boosting: PMMA Booster is kept at 5% to help scatter light and increase the effective SPF and color uniformity.

Recommended Revised Formula (SPF 50 PA++):

Phase A: Silicone & Oil Phase (External Phase)

• Silicone Gel (Ultra Clear, Super Silky): 15.0%
• Silicone Gel (Medium Gloss, Natural Olive Oil Base): 15.0%
• SiliSolve Plus™: 2.5% (Emulsifier)
• LipidSoft™ Lite: 5.0% (Helps dissolve OMC and disperse powders)
• OMC Ultra-Pure™: 10.0% (UVB Filter)
• Zinc Oxide 200nm EasyDisperse™: 10.0% (UVA/UVB Filter)
• Titanium Dioxide 250nm WaterProof™: 8.0% (Physical Filter - Silicone Treated)
• Cyclopentasiloxane: 5.0%
• PMMA Booster: 5.0%
• Vitamin E (Tocopheryl Acetate): 0.2%

Phase B: Powders (Mix into Phase A)

• Beige Iron Oxides EasyMix™: 1.5%
• Mica Powder (Methicone Coated): 3.0%
• MakeGlow™ Powder: 2.0%
• AminoSilk™ (Lauroyl lysine): 1.0%
• MatteSilica 5S™: 1.0%

Phase C: Water Phase (Internal Phase)

• Hyaluronic Acid (1% Solution): 8.0%
• Aloe Vera Extract: 1.0%
• Chamomile Extract: 1.0%
• Preservative: 0.5%
• Fragrance: 0.3%

Mixing Instructions:

1. Prepare Phase A: Mix all ingredients in Phase A together. Use a high-speed mixer to ensure the physical sunscreens (Zinc and Titanium) are perfectly dispersed without clumps.
2. Add Phase B: Gradually add the powders into Phase A and mix until the color is uniform.
3. Prepare Phase C: In a separate container, mix the water, Hyaluronic Acid, extracts, and preservative.
4. Emulsification: This is the most critical step. While stirring Phase A/B at high speed, very slowly drip Phase C into it. Do not pour it all at once. This creates a Water-in-Silicone (W/Si) emulsion, which will be stable and feel silky on the skin.

Note on SPF/PA:

This formula provides high UVB protection (SPF 50) and moderate UVA protection (PA++). If you require higher UVA protection (PA+++ or PA++++), you may consider increasing the Zinc Oxide further or adding a UVA-specific chemical filter.