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Salicylic Acid Blob
I am trying to make a salicylic acid serum with hyaluronic acid powder and keep getting a blob. Can someone tell me what I’m doing wrong? Here’s the formula. I combine the sal acid & prop glycol with gentle heat, in a separate container I heat the water. When both warm, I combine and while mixing in an overhead mixer, I slowly pour in the HYA powder. I end up with a blob. The last 2 ingredients are for the cool down but I never get there. I always end up dumping the blob. I’m sure this has to do with PH, but not sure how to fix. Any suggestions? I’ve also tried adding .066% edta to the water phase but still got the blob.
75.00% water 11.25 2% sal acid 0.3 20% prop gly 3 0 0.63% hya powder 0.0948 0 0.50% g cham 0.075 0.50% sea kelp bio 0.075 98.63% -
17 Replies
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Sounds like maybe the HYA isn’t compatible. Try leaving HYA till the end and then add slowly weighing by difference to see how much HYA you can put in before you get a blob.
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Hi there Assume HYA is Hyaluronic Acid?) Right or wrong I make my Hyaluronic Acid into a solution first (I make a 1% solution with 98.5g Distilled Water, 1g HYA and 0.5g preservative and keep in fridge). So maybe try make the HYA first so it all hydrates first (takes me a few hours the way I do it though). So maybe make your HYA solution with your distilled Water until it hydrates and mix until it is combined - lave to sit until no air bubbles if any present) and then add your other ingredients (do your sal acid and PG as you do now and try mixing these 3 first and see how that goes? I’m only a home maker of products with no fancy equipment but my method may help (or not). Only do a 50g batch first and see how it goes. Cheers
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I think I had the same issue with Glycolic Acid and HA serum/peel.
You might be right - What is your final pH?
My got too low and HA could not handle it (probably) … once I increased it to around 3 - 3.5 (don’t remember precisely) it got ok.Try it. Good luck
PS. I don’t see any preservative? [Not sure what’s g cham]
Make sure, even you are at very low pH (3), you still include some kind of preservative for any opportunistic organism. -
Thank you to both. My first trials of this were with solution of HA. I still got the blob & decided to try the powder instead. As far as the PH, one of my first trials added edta to the water to raise the PH b4 adding the HYA but that didn’t make a difference either.
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I’m sorry, did you say you added EDTA to the water to raise the pH?
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Yes, in one of my trials I added edta to the water before heating
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Yes yes yes!!! I FINALLY figured this out. It was PH. I solved this by checking the PH of the water before I added the HA and making sure it was at least 3.5 and that worked. It took a heck of a lot of EDTA to get it up 1 point so i switched to a couple of drops of TEA which worked faster and then once the PH was 3.5, i added the HYA powder. Got a beautiful serum. Thanks all!
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YAY! I’m happy for you ..
Hm, just … how much EDTA have you added?
Sorry, it’s just … EDTA is not a pH buffer (or at least I never heard of it in this way). It is a chelating agent.
TEA would make much more sense to raise pH.Anyway, happy it worked, … valuable experience
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Absolutely valuable experience for me!! I was working on that one for week. I’ve often heard that whenever you use acids in a formulation, a chelating agent is a good idea. I used .17% in this one and when i saw it wasn’t doing much to raise the PH, I switched to TEA. Just 2 drops. It worked quite well. I think next time, I will still add both. So grateful for all the help and comments I received here! Thank you so much!
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Yes, EDTA does have a high pH of 9+, but I also was surprised to see it being used as a pH up in cosmetics, considering its typical inclusion rate.
Another option other than TEA, if you are looking for label appeal, might be L-Arginine.
Aloha.
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Salicylic acid will precipitate with time because 20% of PG is not enough to keep it soluble. Although since you had raised the pH to 3.5 only around 22% of SA are not neutralized, so it can potentially be enough .
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@Graillotion - Ah yes, L-Arginine. I believe that one is supposed to be good for the skin but probably not in the quantities I’d be using it to raise PH. Still, if I had the choice, its probably better for skin than EDTA or TEA I would guess. @toketsu yes, next time I will go higher on the PG. I would have rather not have neutralized it at all but the hyaluronic acid can’t seem to handle the low PH. It’s funny because I hear mixed things about S.A. Some say it is not at all PH dependent; others say it is. I thank you both for your kind comments!
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I would say that 1:20 ratio of SA to PG is good enough. Even 1:10.
And I would say it is definitely pH dependent - higher pH = salt. pH < 3 = 50% SA bioavailable.
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If you search, you will find some studies on the effectiveness of Salicylic Acid as a function of pH. I think you will find that the effectiveness of SA is not as pH dependent as some may think so long as your pH < 4.5 - 5.0.
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According to “Solubility prediction of salicylic acid in water-ethanol-propylene glycol mixtures using the Jouyban-Acree model” study, solution of 50%/50% water/PG can dissolve 2% SA. So it is more 1:25 ratio. But it for pure SA with low pH.
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Yes, the jury is still out on whether salicylic will be bioavailable at higher PH. I myself have used it at both 4 and 3 PH & find that it seems to work better at a lower PH.
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Hello!
I’m in a little trouble with my SA serum, hope someone might know the solution to my problem.
I have my chelator, preservative, and ~40% Propylene Glycol to dissolve the SA, Betaine, 2% SA and 0.6% xanthan. pH adjusted with NaOH solution to 3.8. Everything is fine, no separation or recrystallization occurs during stability testing, except the 3th cycle of freeze and thaw: I experience gelling up near the dropper. The viscosity of all other parts of the Serum stays the same as the viscosity of the reference sample, pH is also the same, but I experience this gelling up in a line (in all 3 samples).
Has anyone experienced similar? Do you have any idea What can cause this and What might be the solution to this problem? Oh one more thing… I have a sample without SA and betaine, with higher pH (~5), all other ingredients are the same, 3th FT tests are beautiful, same as the reference samples, so I suspect it has something to do with the lower pH of the formula, or the electrolytes…
Thanks!
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