Revised Sunscreen Formula (W/O) Stability and Oil-Fix Recommendation

Question

I have a revised Water-in-Oil sunscreen formula aiming for SPF50, PA++++, easy application, water resistance, and no white cast. My proposed mixing steps are:

A. Dissolve ingredients 1, 2, 3 completely and set aside.
B. Dissolve ingredients 4, 5, 6 completely.

Then combine A, B, and ingredient 7, heating them together. Finally, emulsify with the water phase. My formula includes Vitamin E Acetate (Item 9).

Can this formula be made using these steps, and will it separate?

MySkinRecipes Expert · Accepted Answer

Hello,

Regarding your revised sunscreen formula aiming for SPF50, PA++++, easy application, water resistance, and no white cast, the team has reviewed it and has the following additional recommendations:

Recommendations for the Formula and Mixing Steps:

Placement of Vitamin E Acetate: [url=http://www.myskinrecipes.com/shop/%E0%B8%95%E0%B9%89%E0%B8%B2%E0%B8%99%E0%B8%AD%E0%B8%99%E0%B8%B8%E0%B8%A1%E0%B8%B9%E0%B8%A5%E0%B8%AD%E0%B8%B4%E0%B8%AA%E0%B8%A3%E0%B8%B0/65-vitamin-e-tocopheryl-acetate-%E0%B8%A7%E0%B8%B4%E0%B8%95%E0%B8%B2%E0%B8%A1%E0%B8%B4%E0%B8%99%E0%B8%AD%E0%B8%B5.html]Vitamin E Acetate[/url] (Item 9 in your original list) should be in the oil phase.
Heating the Oil-phase: In the step for dissolving the oil phase ingredients, it is recommended to heat all components of the oil phase (Items 1-7) together at once. This helps in dissolving the various sunscreens more effectively before emulsifying with the water phase.
Enhancing Stability: To prevent separation of the formula, which has a relatively high oil phase percentage (41.5%), the team strongly recommends adding [url=http://www.myskinrecipes.com/shop/emulsifier/1136-water-in-oil-emulsion-stabilizer-oil-fix.html]Oil-Fix[/url] at approximately 1.5% to the formula. Mix [url=http://www.myskinrecipes.com/shop/emulsifier/1136-water-in-oil-emulsion-stabilizer-oil-fix.html]Oil-Fix[/url] in the final step after the oil and water phases have been combined and emulsified, blending for at least 5 minutes to ensure proper dispersion.

Answering Your Questions:

Can it be done: Yes, this formula can be made by adjusting according to the recommendations above regarding the placement of Vitamin E Acetate and the heating of the oil phase.
Will it separate: Due to the high oil phase percentage (41.5%), the formula may be prone to instability and separation. Adding [url=http://www.myskinrecipes.com/shop/emulsifier/1136-water-in-oil-emulsion-stabilizer-oil-fix.html]Oil-Fix[/url] will significantly improve stability and reduce the likelihood of separation.

Additional Notes:

The high oil phase percentage of 41.5% might result in a slightly sticky feel on the skin.
Using a homogenizer with adequate power and speed (as you described) is crucial for creating a stable and smooth Water-in-Oil emulsion.

In summary, your revised formula has the potential to achieve the desired SPF and PA values, but requires minor adjustments in the process and the addition of a stabilizer ([url=http://www.myskinrecipes.com/shop/emulsifier/1136-water-in-oil-emulsion-stabilizer-oil-fix.html]Oil-Fix[/url]) to ensure the formula remains stable and does not separate.

Thank you,
Staff - MySkinRecipes