Home Cosmetic Science Talk Formulating Face serum causes redness with burning sensation.

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  • Face serum causes redness with burning sensation.

    Posted by justcamille on June 19, 2017 at 5:41 pm

    ingredients
    watermelon extract 3%
    Carbopol .5 %
    TEA .8%
    phenoxyethanol .5%
    fragrance .8%
    witchazel 1%
    water 93.4%

    First, I add carbopol into the water using a hand mixer. I’ll stir it using the hand mixer until I can’t see any lumps. Once its somehow thick, I’ll add phenoxyethanol, watermelon extract, witchazel and fragrance still using the hand mixer. Lastly, I will add TEA. I really don’t know if It has something to do with the percentage or how i mix the ingredients. Please help. Thanks!

    justcamille replied 7 years, 4 months ago 5 Members · 9 Replies
  • 9 Replies
  • belassi

    Member
    June 19, 2017 at 6:14 pm

    What is the final pH? Which type of Carbopol?

  • justcamille

    Member
    June 22, 2017 at 11:44 am

    Hi! I just checked the ph its actually 7, what should be the correct ph of my final product?

  • johnb

    Member
    June 22, 2017 at 2:07 pm

    That level of fragrance is very high for a product of this type. Commonly 0.1% or less is used.

    Is this a clear product? If yes, what solubiliser is being used?

    Have you tried a fragrance free version to check on the suitability of the fragrance you are using?

  • justcamille

    Member
    June 22, 2017 at 2:13 pm

    Hi john, it is still clear after adding the ingredients above thats why i did not include any solubiliser. I double checked the ph and its actually 8 not 7. Could it be the ph?

  • OldPerry

    Member
    June 22, 2017 at 2:27 pm

    Phenoxyethanol causes this reaction in some people.

  • johnb

    Member
    June 22, 2017 at 2:36 pm

    I am thinking that your fragrance is pre-diluted with something which is most likely acting as a solubiliser. It is very uncommon for fragrances to be soluble to that extent in, what is effectively, just water.

    pH 8 is somewhat high for a leave-on skin product. Try reducing the TEA level.

    Do also try making some serum without the fragrance.

  • MarkBroussard

    Member
    June 22, 2017 at 6:00 pm

    @justcamille:

    Normally, depending on the type of Carbopol you are using, the ratio of Carbopol/Neutralizing Base is about 1:1.  So, try dropping the TEA down to 0.5%.

    Yes, pH 8.0 is way too high for a leave-on product for the face.  Once your carbomer gel form, let it sit for a bit, and then add some Citric Acid solution to bring your pH down to the 5.5 to 6.0 range.  The stability will be a function of the type/grade of Carbomer you are using.

    You might try switching to Lubrizol Ultrez-30 which is designed for lower pH systems.

    What you’ll want to do is make one batch without the Fragrance, one batch without Phenoxyethanol and one batch without both Fragrance and Phenoxyethanol … all at the same pH to figure out what is causing the problem … either the pH, the Fragrance or Phenoxyethano, or both the Fragrance and Phenoxyethanol.

    I suspect excess TEA is what’s causing your issue.

  • justcamille

    Member
    June 23, 2017 at 12:12 am

    i have been paying per liter of this type of serum that is made by a lab here. Their formula was actually great. I asked their ingredients and we have all the same ingredients, i got the fragrance from them (watermelon fragrance) which they use when I order 10kilos of their serum. They also use phenoxyethanol as a preservative, so i guess my only problem right now is the ph level, i will reduce the % of fragrance and TEA. 

  • justcamille

    Member
    June 23, 2017 at 12:13 am

    You have been all very helpful, im glad i get to join here. 

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