Substituting SPF Protect Ultra with SPF Protect Ultra II

You asked if you can substitute SPF Protect Ultra with SPF Protect Ultra II in your sunscreen formula using Milk Lotion Maker and avoid the heating step.

Based on the information available, SPF Protect Ultra II also requires heating (70-80°C) to properly dissolve and achieve its full sun protection effectiveness. While SPF Protect Ultra II does not require an additional emollient like LipidSoft for dispersion (as the emollient is already included), the heating step is still necessary for the sunscreen active itself to incorporate correctly into the oil phase and provide the stated SPF/PA values.

Therefore, simply swapping SPF Protect Ultra for SPF Protect Ultra II in your formula will still necessitate the heating step as outlined in the instructions for both Milk Lotion Maker and SPF Protect Ultra II.

Additionally, please note that LipidSoft Dry is discontinued, and LipidSoft Dry II is recommended as a replacement. However, using LipidSoft Dry II instead of LipidSoft Dry does not change the requirement for heating the sunscreen active.

In summary, to create a stable and effective sunscreen lotion using Milk Lotion Maker and SPF Protect Ultra II, the heating step for the oil phase is essential.