Substituting SPF Protect Ultra™ II with SPF Protect Ultra™ III and the Resulting SPF Value
Question
I am planning to formulate a sunscreen lotion using the following components:
1. `SPF Protect Ultra™ III (UVA+UVB)` 15% (Used to replace `SPF Protect Ultra™ II` 15%)
2. `Milk Lotion Maker` 3%
3. `Satin Cream Maker` 0.7%
4. Water 80.3%
5. `Mild Preserved Eco` 1%
Can `SPF Protect Ultra™ III (UVA+UVB)` be used to substitute `SPF Protect Ultra™ II` at a 15% concentration in this formula, and what would be the expected impact on the final SPF and PA rating compared to the original formulation?
Answer
Yes, you can substitute SPF Protect Ultra™ II with SPF Protect Ultra™ III (UVA+UVB) in the provided formula, as both are oil-soluble sunscreen bases designed for use in the oil phase of an emulsion. The mixing process remains the same.
However, you should be aware of the difference in sun protection (SPF) efficiency:
- Original Formula (SPF Protect Ultra™ II at 15%): Provides a minimum of SPF 50, PA++.
- Substituted Formula (SPF Protect Ultra™ III at 15%): Based on the product data (10% = SPF 20-25, 20% = SPF 50), a 15% concentration is estimated to yield an SPF of approximately 35-40.
Conclusion: The substitution is technically possible, but the resulting sunscreen will have a lower SPF value than the original formula. If you require SPF 50, you would need to increase the concentration of SPF Protect Ultra™ III to approximately 20%.
The mixing steps are the same:
- Mix SPF Protect Ultra™ III (15%) with Milk Lotion Maker (3%) and warm to 70°C (Oil Phase).
- Warm Water (80.3%) to 60-70°C (Water Phase).
- Add the Water Phase slowly into the Oil Phase while blending for at least 15 minutes.
- Add Satin Cream Maker (0.7%) and whisk until dissolved.
- Add Mild Preserved Eco (1%).
Related Products Mentioned
SPF Protect Ultra™ II
