Home Cosmetic Science Talk Formulating Formulating a sunscreen for the first time

  • Ghita37

    February 8, 2023 at 6:45 am

    I read long ago about some chemical filter that is safe but dont recall the name. If someone knows can they please share? The reason why im asking cus im telling myself a 100% mineral SUNSCREEN TO BE FULLT effective must have a high % of zinc but this latter leaves a chalky skin so why not mixing mienral and chemical filters but then i dont remember that chemical filter i read about that is safe.The problem now we dont know which source is reliable to tell us what is safe and what is not and this is so frustrating.

    Also yesterday i was reading an article written by the Lab Muffin and she was talking about clean beauty/She said that so many ingredients are hazardous but its their exposure that should matter.I think by exposure she means how much are we going to put to formulate the product/So does that mean even the 6 banned chemical filters by the FDA might not be harmful if we are using them is small dosage?


    Thank you all

  • Lab

    February 8, 2023 at 7:07 am

    Hi Ghita!

    Always follow FDA recommendations in a matter of %. They list chemical and physical filters that are safe and also their maximum allowable concentration. If it has been approved by the FDA, it is safe. Period.

    There are several cosmetic ingredients that you can find that are blends of filters, for example - maybe you can find something interesting in them.

    To cite some trade names in general that I usually work with (you can check the INCI in the links below):

    Please remember that the laws in force in my country (Brazil) are different from those established by the FDA, so I cannot tell you off the top of my head which filters are allowed in the USA and their concentrations. I’ve never had a problem with any of the above in my country and we’ve always followed ANVISA (our regulatory body) rules. Therefore, some research will be required on your part.

    About sun exposure: regardless of your filter’s FPS, ideally there should be reapplication at most every 2 hours. Regardless of whether it is 30 FPS or 70 FPS. Always reapply.

    Oh, and if I may ask, how are you sure this filter is SPF 50? Did you carry out a test in a specialized laboratory or is it an estimate from a sun protection calculator?

    Greetings! 😌

  • microformulation

    February 8, 2023 at 7:11 am

    Don’t make your own sunscreen unless you are experienced. It will require specific mixing energies, the Formulations entail much more than just how much the “active” to add as other materials, and it must be tested. Unless you are in a Commercial lab with the proper knowledge, personnel, and testing support, go buy a tested and effective product.

    I would wager that you will/should get similar advice from other Professionals in the discussion.

  • markbroussard

    February 8, 2023 at 7:24 am

    Yes, sunscreens are not good formulas for non-professionals to experiment with. In the US, Sunscreens are regulated as OTC products and the total cost to do all of the required testing to get a new sunscreen to market is in the range $75,000 to $100,000. A major component in grading the SPF of a sunscreen is even distribution of the mineral sunscreen active when applied to the skin. As @Microformulation pointed out, this requires some level of sophistication in processing the ingredients.

  • ketchito

    February 8, 2023 at 9:02 am

    As many pointed out here, don’t try formulating a sunblocker without the proper knowledge. They are within the most difficult products to formulate. Just as an example, you need to know the ratio of UVB/UVA protection according to new rulings, and that you only get when sending the sample to a certified laboratory. You need to also check the photoprotection during shelf life and photocatalytic activity of your molecules. If you plan to formulate using only inorganic materials, you will fall short (many studies have shown that only-mineral sunblockers provide only a limited SPF, even when using high amounts of ZnO or TiO2…and this is even choosing different particle size filters and using high levels of humectants to help spread them more evenly. Then, there comes the type of emulsion which also impacts both performance and the preservative efficacy.

    Now, what FDA said about the organic filters is that there is not sufficient evidence to classified them as GRASE, not that they cannot be used. There are many studies going on to reevaluate their safety, but under a risk assessment, it’s better be protected from UV rays that have limited protection.

  • fareloz

    March 9, 2023 at 4:15 am

    How can we report this user for ads?

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