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Need some help with redness
Formula (w/w) in grams
Distilled Water` 67.5%
Glycerin 15%
Versagel 5%
Cetearyl Alcohol 4.2%
Ceteareth-20 1.8%
Shea butter 2.5%
Macadamia nut oil 2%
Sodium PCA 1%
Tocopheryl Acetate 1%
Itching - None
Redness - Very high
Moisturizing – Enough but burns a lot
No. of days tested – 3
pH – Not tested
Preservative – Not added
As mentioned the formula caused intense redness on my face, this formula is an attempt to make something similar to the old Cetaphil DAM (only for personal use).
Process:
1.) Heating Cetearyl Alchohol, Ceteareth-20, Shea butter, Macamadia nut oil, Versagel together till melted
2.) Adding distilled water (not heated) slowly while stirring
3.) Adding glycerin, Sodium PCA and Tocopheryl Acetate during the cooldown phase.
My only qualm with this formulation is that it caused a lot of redness and stinging.
I haven’t tested the pH yet and I am assuming that this might be the culprit.
*I AM NOT A COSMETIC CHEMIST JUST A STUDENT THAT IS TRYING TO REPLICATE A PRODUCT*
Any hints to what might the problem be and ways to tackle this issue?
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6 Replies
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pH itself is not an issue, but the use of higlhy basic or acid substances, which are not present in your formula.
There’s nothing really obvious, but I’d advise to greatly reduce Glycerin (15% is too much, you could use around 5%). Also, Tocopheryl acetate is too high (it’s not active as antioxidant to protect your formula, and in your skin it still needs to be converted), I wouldn’t add more than 0.2%. Ceteareth-20 is also very high (you don’t need more than 0.5% depending on your oil phase, which in your case is not too high). And don’t forget to add a broad spectrum preservetion system, even if you’re still designing your formula.
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I agree pretty much with the above comments. It looks pretty much like a “sorbolene” cream with a little more glycerin. I don’t see much to irritate but the absence of a preservative is a worry. And with such a small oil phase I agree the emulsifier content could probably be reduced.
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I would have to assume…you have applied all individual ingredients by themselves on your skin….to make sure you do not have an allergy?
So try these by themselves on your face:
Glycerin
Versagel
shea butter
Mac Nut oil
Then mix the following into water at the correct ratio…. Water + PCA + TocoAcetate
See if any if any these create a response.
If not …. consider swapping the emulsifier package.
This is kind of a ‘topical knockout experiment’.
Aloha.
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I would definitely try the ingredients neat to see if it’s a reaction. But don’t use anything neat that isn’t safe to use at 100%. My skin doesn’t like glycerin, I can only use small amounts, usually under 2%. I believe glycerin can cause warmth at a high percentage, and the amount you are using is a lot for a leave on product. Do you usually have reactive skin? Do you have any allergies?
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Thank you everyone after testing each ingredient at 5%. It was versagel that was the problem. Now I’ll buy hydrogenated Polyisobutene in isolation to test if that reacts.
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Thank you for the update.
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