Home Cosmetic Science Talk Formulating Vitamin C Serum - Ferulic Acid Crystallizes

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  • Vitamin C Serum - Ferulic Acid Crystallizes

    Posted by halrac on November 23, 2017 at 1:03 pm

    Hi everybody!

    I keep on trying to making a Vit. C serum that I can use https://chemistscorner.com/cosmeticsciencetalk/discussion/3413/combination-of-geogard-221-leucidal-liquid-sf#latest and I have tried to simplify it as
    much as possible.

    Last weekend I thought I had found the perfect/good enough for me recipe for a
    30ml bottle:

    Distilled Water  
                             20 grams

    L- Ascorbic
    Acid                   
          4
    grams

    Glycerin                                
          1%

    Ferulic
    Acid                                 0,5%

    Sodium Hyaluronate
    (RMW)          0,2%

    1,3-Propanediol
    2                 
         20%

    Green Tee
    Extract                  
         1%

    Xaromix or Geogard
    Ultra            1%
    or 2%


    I have had problems
    dissolving the Geogard in the past, so this time I went for the Xaromix.

    Everything seemed good, but after two days, small long filaments could be seen
    in the bottle. I had seen them before, so I knew that it was the Ferulic Acid.
    My question is, why? I mixed it with
    Propanediol and warmed it up to 70ºC and I did not use anything metallic.

    Any ideas?

    Thank you very much in
    advance,

    halrac

    halrac replied 6 years, 10 months ago 8 Members · 19 Replies
  • 19 Replies
  • halrac

    Member
    November 24, 2017 at 10:56 pm

    I was wondering if nobody is replying because this is a silly question or because you need more information…

  • belassi

    Member
    November 24, 2017 at 11:20 pm

    I am not familiar with ferulic acid. Does this happen with both of the preservatives?

  • MarkBroussard

    Member
    November 24, 2017 at 11:24 pm

    I suspect your problem is actually the Geogard Ultra and/or Xaromix as opposed to the Ferulic Acid.  Try switching to a liquid preservative … 

    Add 6% Sodium Lactate to your water phase, heat it to 80C, and then add the Glycerin/Ferulic Acid slurry.  Add the Ascorbic Acid last.

    That will probably solve your problem.

  • Doreen

    Member
    November 25, 2017 at 3:40 pm

    Did not use anything metallic?  What do you mean by that?

    I agree with Mark, you need something like sodium lactate, it’ll keep the ferulic solubilized. What is your final pH btw? Sodium lactate is a buffer and raises the pH. Lotioncrafter also has a vitamin C/ferulic formula (they sell DIY vitamin C serum packages, very similar to Skinceuticals C/E Ferulic). They suggest triethanolamine without even heating the ferulic solution.
    A tip: I have a formula with ferulic acid (no vitamin C though), it also has 5% niacinamide and it doesn’t even need sodium lactate: the high % of niacinamide keeps the ferulic solubilized. I got this tip from @johnb. The final pH of that serum is 4.7-4.9.

    About the Geogard 221 solubilization troubles: I only use it as a booster at 0,15-0,2% (mostly because of the awful smell and that’s easy to mask with a fragrance at that %).
    What kind of microbiological test do you do to test the efficacy of your preservative system? Do you do challenge tests?

  • DRBOB@VERDIENT.BIZ

    Member
    November 25, 2017 at 5:08 pm

    Ascorbic acid is too high;try reducing to half first ie from 4 parts to 2 parts.You can also replace it with sodium ascorbyl phosphate.Change preservative to germaben at 1%.

  • halrac

    Member
    November 26, 2017 at 10:46 am

    Hi Belassi! Yes, it happens with both preservatives.

    Hi MarkBroussard! The Xaromix is liquid but I will
    add the sodium lactate as indicated and add the ingredients in the suggested
    order.

    Hi Doreen81! I read somewhere that using metals when
    ferulic and/or L-ascorbic were involved in a formula could be an oxidizing
    fact. The first time that I tried making this serum I used a milk frother whisk
    to mix the ferulic acid with glycerin, and when I added the ascorbic acid, I immediately
    saw it crystalizing.

    With regard to the pH, mine was 3.5 when I last made it.

    I am afraid that I do
    not run any microbiological test. I make small batches and they last one month
    approximately. I do not sell this serum or anything like that, it is for
    personal use.

    Hi DRBOB@VERDIENT.BIZ, though I am going to keep on
    trying using the L-ascorbic acid, I have a formula with sap that I may try in
    the future.

    Thank you all very much for your help! I have taken very good note of
    everything that you have said and I will keep you updated with my progress!

  • Maes

    Member
    November 26, 2017 at 11:42 am

    As your pH is below 5 you could try to use MICROCARE SB as a preservative. It doesn’t give many problems (or not to me until now).

    If the % of vit C is high remember we would probably have to add a citric (citric acid, sodium citrate) buffer  to stabilize the pH.

    About the ferulic acid…sorry I do not have experience with it.

  • halrac

    Member
    November 27, 2017 at 12:16 pm

    Hi Maes! Thank you very much for your reply.

    At one point, I studied the possibility of using Microcare SB, problem is the recommended pH is 4-6 and my serum, in order to be effective, needs to be 3.5 or lower.

    On a different note, I do not why, but when I saw you your profile photo I though: “That girl looks Spanish!”.

    Greetings from Málaga! ;)

  • Doreen

    Member
    November 27, 2017 at 4:30 pm

    @halrac
    It’s ok to go below pH4 with Microcare SB (sodium benzoate, potassium sorbate), actually it’s even better. These are the sodium and potassium salts of benzoic and sorbic acid and they need an acidic environment to convert to their acid form. At pH>5 they are no longer active. pH 3.5 is great.
    They are unsaturated fatty acids, so you’ll need an anti-oxidant like BHT.
    It also isn’t broad spectrum, you’ll need something against bacteria too.

    FYI there have been worries about benzene forming when combining sodium benzoate/benzoic acid with ascorbic acid, but it’s ok to use these together. Concentrations are low enough not having to worry about it, benzene forming also happens naturally. (Cranberries for example contain both benzoic acid and vitamin C).
    Just like formaldehyde releasers, concentrations in cosmetics are very low (comparable to formaldehyde levels found naturally in vegetables and fruits e.g. pears and grapes).

  • Bill_Toge

    Member
    November 28, 2017 at 8:21 pm

    further to @Doreen81’s comments about benzene formation, I might also add this reaction only happens in the presence of iron, because the iron acts as a catalyst: as a reducing agent, ascorbic acid on its own is nowhere near powerful enough to reduce benzoic acid to benzene (if it were, it would be much more hazardous, both to human health and in general)

    if you use deionised water and a chelator, the concentration of iron in the product will be somewhere between undetectable and nothing at all

  • Doreen

    Member
    November 29, 2017 at 7:28 am

    I forgot about the organic acids becoming less water soluble in their acidic form, sorry! Maybe pH 3.5 is indeed too low as they might give precipitation and become useless. Parabens would be a great choice for you as they are effective, safe and less pH sensitive.

    @Bill_Toge
    Thank you for adding the information about iron as catalyst in the reaction. It also makes al lot of sense why they did worry about it in the softdrink industry as 1. the benzene will be ingested and 2. I reckon they don’t use demineralized water for soda, so catalyst(s) are present. Do all transition metals act as reducing agents in this reaction, or is it only iron?

  • em88

    Member
    November 29, 2017 at 7:58 am

    Is acid ascorbic stable in that formulation?

  • Doreen

    Member
    November 29, 2017 at 8:43 am

    @em88
    No it isn’t stable. Intentions aren’t for selling, it will be used within a month.

  • em88

    Member
    November 29, 2017 at 8:59 am

    Now it makes more sense :) 
    Thank you

  • Doreen

    Member
    November 29, 2017 at 9:22 am

    @em88
    You’re very welcome. :-) 

  • Bill_Toge

    Member
    December 1, 2017 at 10:47 pm

    @Doreen81 iron and copper are the most likely culprits; other catalytically active transition metals (manganese, platinum, palladium etc.) are typically present at such low levels, assuming they’re present at all, that they have little if any effect

  • Doreen

    Member
    December 8, 2017 at 2:46 pm

    @Bill_Toge
    Ok, thanks for the information!

  • Doreen

    Member
    December 12, 2017 at 2:40 am

    @halrac
    Have you made progression so far?

    Re: organic acids and pH.
    Today I made a 2% BHA toner (benchmark Paula’s Choice 2% BHA liquid pH 3.2-3.8). PC doesn’t use additional preservatives in this formula besides the polyols and salicylic acid, but I wanted to incorporate at least something against yeast/mold, so I tried benzoic and sorbic acid on a selected part of the batch.
    The native pH was well below 3, I raised it with NaOH to 3.76. This seems to be too acidic for the acids (except for SA). As soon as I added the acids to the crystal clear solution, it started to precipitate and the insoluble matter floated on top of te liquid. So even a pH of 3.76 is too acidic for them. I thought I’ll let you know, maybe it’s helpful for you or someone else on here.

  • halrac

    Member
    January 11, 2018 at 10:46 am

    Hi everybody,

    I like to keep you updated with my progress (it is also a way to show you my gratitude for all your help).

    I made a new batch 3 weeks ago and it turned out perfect (at least, from my point of view).

    This is the new recipe:

    Distilled Water                     20g
    L-Ascorbic Acid                   4g
    Glycerin                               1%
    Ferulic Acid                          0,5%
    Sodium Hyaluronate (RMW)  0,2%
    1,3-Propanediol                   20%
    Green Tee Extract                 1%
    Sodium Lactate                     6%
    Citric acid                             q.s.
    Xaromix                                1%

    I added sodium lactate as MarkBroussard suggested, added the L-Ascorbic Acid last and used xaromix as opposed to Geogard Ultra (dissolving it properly is almost impossible for me).

    I believe that, due to addition of the sodium lactate, my final pH was around 4, so I decided adding a little bit of citric acid. I was hesitant at first as I did not know if the final product would be too harsh on my skin, but after giving it some thought and do some research, I went for it.

    The serum is really nice, up until today there is no visible oxidation and the “filaments” are now history.

    In order to make things a little bit more complicated I was thinking of adding disodium EDTA next time as a chelator. Any thoughts?

    Edit: Formatting

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