Home Cosmetic Science Talk Formulating MAP/SAP vs L-ascorbic acid

  • MAP/SAP vs L-ascorbic acid

    Posted by stanley on July 18, 2021 at 5:21 pm

    When switching L-ascorbic acid out of a formulation and using either MAP or SAP…is it a 1:1 ratio?  Should you use less or more MAP/SAP.

    markbroussard replied 2 years, 8 months ago 3 Members · 7 Replies
  • 7 Replies
  • markbroussard

    Member
    July 18, 2021 at 6:34 pm

    @Stanley:

    You will be able to more approximate a 1:1 substitution of Ascorbic Acid with SAP than with MAP.  The reason is that MAP, when used at anything above 7%, will leave a white film on the skin (and your equipment), so that would be an upper limit on MAP as it affects your product’s consumer acceptability.

  • stanley

    Member
    July 18, 2021 at 9:54 pm

    @MarkBroussard
    So trying to make a 20% serum would be not possible.  I am trying to prevent L-ascorbic acid from turning brown so quickly.  Would it be possible to use MAP at 6% and L-ascorbic acid at 14% in my serum?  I have MAP available to me right now.

  • markbroussard

    Member
    July 18, 2021 at 10:26 pm

    @Stanley:

    I would first consider a couple of questions:

    (1)  Why 20% Vitamin C?  More is not better … enough is enough should be your guideline in developing your product.  I would advise you to not get hung up on 20% Vitamin C, but instead suggest you research what is the optimal amount of Vitamin C to use for each of the various variants of Vitamin C.

    (2)  There are few ways to delay the oxidation of Ascorbic Acid in aqueous solutions … You might want to study patents on the stabilization of Ascorbic Acid.

    I would frankly avoid using MAP altogether as it is more difficult to formulate with than SAP.

  • stanley

    Member
    July 19, 2021 at 2:50 am

    @MarkBroussard
    I appreciate your words.  I am being asked to reproduce a Vitamin C formulation that was at 20%.  The initial work is proving to be not reproducible and leaning toward being flawed. I have looked at different patents on the subject matter.  I am also trying to be a little innovate in thinking through other solutions.  I do expect this to turn colors quickly but I am also trying to have something viable to present. 

  • markbroussard

    Member
    July 19, 2021 at 2:57 am

    @Stanley:

    I see your predicament.  The issue with trying to combine Ascorbic Acid with SAP or MAP is that they function at different pH levels, so you have a fundamental conflict in trying to combine those ingredients.

    So your development model is a Vitamin C Serum with Ascorbic Acid loaded at 20%?

    I find the quest to use an indordinately high level of Vitamin C somewhat amusing as it is merely a marketing gimmick and has nothing to do with the optimal effectiveness of the product.

    My sympathies to you.

  • ngarayeva001

    Member
    July 19, 2021 at 5:53 am

    MAP will not dissolve at 20% and you will have precipitation. Also those are derivatives that are converted into LAA by one’s skin, it is nearly impossible to predict how much would convert and how much would be lost. 

  • markbroussard

    Member
    July 19, 2021 at 1:11 pm

    @ngarayeva001

    Correct, I think the max solubility of MAP is 7.5% … it’s just a mess of an ingredient to work with.

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