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Best SPF Boosters for Zinc Oxide formulas? Methylcellulose, Styrene/Acrylates Copolymer ++
I’m investigating SPF Boosters, non-drug ingredients that either help disperse the actives on the skin, form films, scatter light or actually absorb UV radiation. The formula in question is for now a simple oil in water emulsion with Caprylic/Capric Triglycerides, Ewax NF (or Olivem 1000 or similar), a Zinc Oxide Jojoba Ester, Polyhydroxystearic Acid dispersion, some humectants, gum, antioxidants and preservative. Possibly also film formers like Candelilla wax.
Methylcellulose sold under the Solterra brand: http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_08b5/0901b803808b5946.pdf?filepath=suncare/pdfs/noreg/324-00321.pdf&fromPage=GetDoc
20% Zinc Oxide formula gets SPF39 with 2% of it and SPF33 with 1%, doesn’t seem impressive and could this effect just be attributed to the gel forming and be emulated by other gelling thickeners?SunSpheres™ Powder Styrene/Acrylates Copolymer claims it helps scatter light.
What else should I look into?
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5 Replies
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Silicone boosts SPF, get info from google. e.g. Cyclopentasiloxane and silicone elastomers.
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I’ve used sunspheres in my spf formulations for clients and it did raise the SPF.
You’ve probably seen amphisol K in a lot of sunscreen formulas as that is marketed to boost SPF.
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I have used the Sunspheres successfully in the past as well.
One note: Even if the sample Formula projects an SPF value, you still must have the Formula tested. You can not extrapolate the final SPF.
Lastly SPF is only one factor, Spectrum must be considered also.
I have never seen silicones used to boost SPF, outside their use as spread enhancers. NEVER use Google as your research tool.
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There’s a silicone coupled to a sunscreen that’s a booster (PARSOL® SLX) - that might be a possibility.
Hallstar has a few options:
https://www.hallstar.com/webfoo/wp-content/uploads/Hallstar_Sun_Care_Brochure_2015.pdf -
@MakingSkincare in zinc oxide based sunscreens? What kind of boost did you see? All of DOW’s examples are for chemical sunscreen formulations.
@Microformulation For the in vitro (not 10 subject challenge test for FDA) testing we’ll get UV-A and B abs done. Re silicones, I’ve seen claims that the right silicone can improve SPF in mineral sunscreen formulas two-fold, but it’s possible the formula had poor pigment dispersion to begin with.
@Bobzchemist thanks, I didn’t find anything too promising with Hallstar although it’s interesting that they recommend Olivem 1000 as an emulsifier in sunscreen applications (used by Epicuren in their excellent formula). Parasol SLX could be interesting if incorporating silicones. Thx.
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