Sunscreen Formulation Adjustments with SPF Protect Ultra™ II

Thank you for sharing your sunscreen formulation and questions. Here's how you can address the texture and foaming issues, and explore alternative textures while using SPF Protect Ultra™ II at 15%.

1. Adjusting Viscosity (Making it thicker)

Your current formula uses Milk Lotion Maker™ and Satin Cream Maker™ as emulsifiers and thickeners. To achieve a thicker texture similar to an SPF90 product, you can try the following adjustments:

• Increase Satin Cream Maker™: The description for Satin Cream Maker™ suggests increasing its percentage (e.g., to 1.5% or 2.0%) to achieve a thicker cream. It is used in the water phase and helps thicken the formula.
• Increase Milk Lotion Maker™: While primarily an emulsifier for high oil content, increasing Milk Lotion Maker™ (e.g., to 4% or 5%) can also contribute to increased viscosity. It is used in the oil phase and helps bind the oil and water.
• Add Waxes or Fatty Alcohols: The description for Milk Lotion Maker™ mentions that adding waxes (like Beeswax, Microcrystalline Wax) or fatty alcohols (like Cetearyl Alcohol, Glyceryl Stearate SE) at 2-10% can thicken the cream. These should be dissolved in the oil phase with heat (around 70°C).

Experiment with these options, starting with small adjustments, to reach your desired viscosity.

2. Reducing Foam

The presence of foam can often be related to the mixing process. Your formula uses Satin Cream Maker™, which is specifically noted for its ability to absorb bubbles.

• Reduce Mixing Speed: The instructions for Satin Cream Maker™ advise against mixing above 2500 rpm to avoid damaging the polymer. High-speed blending can incorporate air and create foam. Ensure you are not using excessive mixing speed, especially after adding Satin Cream Maker™ and during the cooling phase. The instructions for Milk Lotion Maker™ also suggest blending without using high speed during cooling.

By reducing the mixing speed, you should see a significant reduction in foam.

3. Alternative Textures with SPF Protect Ultra™ II (15%)

You can definitely create different textures while keeping SPF Protect Ultra™ II at 15%. The final texture (lotion, cream, gel-cream, spray) is primarily determined by the emulsifier system and other rheology modifiers used.

• Change the Emulsifier System: To achieve a different texture, you would need to replace or combine Milk Lotion Maker™ and Satin Cream Maker™ with different emulsifiers or thickeners. For example:
  • For a lighter lotion or spray, you would need emulsifiers suitable for lower viscosity formulations.
  • For a gel-cream, you might use gelling agents in the water phase combined with an emulsifier.
• Consider Compatibility: Remember that SPF Protect Ultra™ II is oil-soluble and requires heating to 70-80°C in the oil phase for proper dissolution and full sun protection performance. Any new emulsifier system must be compatible with this heating step and the oil phase containing SPF Protect Ultra™ II.
• Explore Different Ingredients: Different emollients and texture modifiers can also significantly impact the feel and spreadability of the final product.

Developing a completely new formulation requires careful selection of compatible ingredients and testing. While I cannot provide a specific alternative formula without further development, exploring emulsifiers designed for the texture you desire (e.g., lighter lotions, sprays, gel-creams) and ensuring compatibility with the required heating step for SPF Protect Ultra™ II is the correct approach.