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Struggling to get ascorbic acid to dissolve in C/E/ferulic acid serum
First of all, yes, I know vitamin C is unstable and hard to formulate with and I should just buy one off Amazon… but I’m not gonna listen to that advice 😛
So, I’ve been trying to make a C/E/ferulic acid serum based off of Lotioncrafter’s formula. I upped the ascorbic acid from 15% to 20% and removed 5% from the water. I also removed the panthenol and upped the water accordingly. And I’m using NaOH instead of TEA.
Every time I add the ascorbic acid, I’m unable to get it to dissolve. The solution is full of white flakes. I test the pH and it’s about 4.5 before adding any NaOH, so clearly, there’s a lot less than 20% ascorbic acid in solution. I did an experiment: 20% ascorbic acid, 20% ethoxydiglycol, 10% propylene glycol, and 50% water. Again, it didn’t fully dissolve, and the pH was much higher than I’d expect. I did another experiment: 20% ascorbic acid, only 10% ethoxydiglycol, 70% water. Voila: a crystal-clear solution.
I looked up the solubility of ascorbic acid and found that it’s 33%/wt in water, and only about 5% in glycols. This meshes with the results of my experiments. But one member posted here advising another member to avoid using water at all and make a serum using only (I think 15%?) ascorbic acid and propylene glycol. They claimed that ascorbic acid can dissolve in propylene glycol at up to 17% (uh, citation needed…).
My question is: how on earth are you all (and the brains behind the patented C/E/F formula) managing to dissolve 20% ascorbic acid in a serum that has less than 50% water (or even 0% water) when it seems to require much more water than that?
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7 Replies
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They claimed that ascorbic acid can dissolve in propylene glycol at up to 17% (uh, citation needed…).
It’s true, I’ve seen some patent stating that. The solubility in propylene glycol can increase in presence of Urea.
how on earth are you all (and the brains behind the patented C/E/F formula) managing to dissolve 20% ascorbic acid in a serum that has less than 50% water
Are we? Skinceuticals sell 15% formula. Lotioncrafter states 15%. It’s only you who tweaked the formula to get 20% ????
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<deleted>
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The Timeless formula is 20%.
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We don’t know their formula, mostly sure they just use enough water.
We know only formulas from Lotioncrafter and L’Oreal’s patent for CEF serum. And they don’t go over 15%.
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I can’t figure out how to edit my reply on mobile. I don’t think adding urea (another super finicky ingredient) is the solution I’m looking for, but I appreciate that. I’ve never seen anyone here mention anything about vitamin C needing a certain amount of water (or some other ingredient) to dissolve — I’ve only seen them warning to use little or no water — so I wanted to confirm my suspicions.
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I don’t think adding urea (another super finicky ingredient) is the solution I’m looking for
It’s not a suggested solution, just a remark from the same patent where solubility in PG is mentioned. The whole patent was about increasing solubility in PG using Urea.
If you want to have a source about PG solubility, here is the patent: https://patents.google.com/patent/US20070077261A1/en
It says:
It was also determined that in a composition comprising, by weight, 17% ascorbic acid and 83% propylene glycol prepared by heating the mixture at 75.degree. C., the ascorbic acid was soluble under this experimental condition. This result is consistent with the solubility data disclosed in U.S. Pat. No. 6,361,783.
patents.google.com
A method for dissolving ascorbic acid in a nonaqueous alcohol solvent using a solubilization enhancer is described. The amount of ascorbic acid solubilized in the nonaqueous alcohol solvent containing the solubilization enhancer is greater than the amount of ascorbic acid … Continue reading
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You’re falling into the “more is better” trap. It is well established that 15% L-Ascorbic Acid is the optimum amount. The additional 5% LAA that you are trying to add will not make the product better.
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