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Feedback on my niacinamide “toner”?
Hello- I am just getting started studying cosmetic chemistry to formulate for myself/friends/family. My first attempt is a simple “toner” - no cleansing desired; just brightening and hydrating. Two questions: since everything is water-soluble, I don’t need a solubilizer or antioxidant, correct? Do I need a chelating agent with this small amount of aloe concentrate? Any other feedback? Thank you so much!
Distilled
water83.05 Niacinamide 5 Urea 5 Aloe Vera
concentrate (10x)1 Glycerin 2.5 Propanediol 2.5 Allantoin 0.25 Hexanediol 0.7 Lactic acid to adjust pH to 5.5
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8 Replies
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Since you are using aloe vera, you might want to add a chelating agent, though you would also want a more robust broad spectrum preservative besides from the diols you have.
You would also need a buffer for the urea since it will increase the pH as it causes pH drifting over time.
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You need chelating agent anyway as part of your preservative system speaking of which, I understand you rely on diols here. I am no expert by any means, but it doesn’t look sufficient to me especially with aloe added (aloe introduces additional preservation challenge). Other than that, your toner looks ok to me. I make a serum very similar to this (urea, niacinamide, sodium lactate, lactic acid, other humectants). I keep ph at 6 and thicken it with high molecular weight hyaluronic acid.
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This is super helpful. Thanks so much.
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Yeah, you need a proper preservative and a chelating agent (like disodium EDTA)
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jemolian said:Since you are using aloe vera, you might want to add a chelating agent, though you would also want a more robust broad spectrum preservative besides from the diols you have.
You would also need a buffer for the urea since it will increase the pH as it causes pH drifting over time.
Hi, I made a toner and used urea in that. I have a problem with pH instability, I need help to form a urea buffer.
Can I use tetrasodium edta instead disodium edta? because I have other acidic ingredients and need increase pH and adjust it in 5 around.
thanks a lot -
You can use whatever form of EDTA you like because, once you adjusted pH, they will all become the same.The optimal pH for urea is 6.2. In theory, you’d need a buffer which has a pKa between 5.2 and 7.2. Upon degradation, urea tends to increase pH which means a buffer with a pKa of 5.2 will not work. Therefore you’re limited to buffers in the range of pKa ~6 to ~7.2. Notably, you’d need quite a bit of buffer… use something well tolerated. Good’s buffers can come in handy.One trick which can work (I guess mostly if combined with a buffer) is triethyl citrate or triacetin. These will hydrolyse if pH rises and thereby release acids which lower pH back. -
jemolian said:For the buffer, you can see if the info here helps
Thanks a lot
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