Home Cosmetic Science Talk Formulating Can this ingredient list be correct? - Vitamin C serum

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  • Can this ingredient list be correct? - Vitamin C serum

    Posted by fromcstocs on December 28, 2018 at 5:37 pm

    I am currently a cosmetic chemist student and wondering more and more if some ingredient lists are chemically feasible. For example, this one is claimed to be a 23% Vitamin C serum:
    Water, L-Ascorbic Acid, Alkyl Benzoate, Panthenol-D, Carbomer, Ferulic Acid, Sclerotium Gum, Optiphen, Hyaluronic acid

    As far as I understand, everything is water soluble except for Alkyl Benzoate. Or is there a water-soluble Alkyl Benzoate? Or is it  C12-15 Alkyl Benzoate?  If the latter where is the emulsifier?  I also do not see any ingredient that would set correctly the pH of the formula for 23% Vitamin C.

    What do you think? Can this be a correct ingredient list and if so how? 

    Microformulation replied 5 years, 5 months ago 3 Members · 5 Replies
  • 5 Replies
  • Microformulation

    Member
    December 28, 2018 at 5:44 pm
    The C12-15 Alkyl Benzoate is puzzling and I can’t see how it is incorporated into the aqueous partition as well.
    As far as the overall Formula, pull up the original Patent from L’Oreal. They have the IP for stabilizing L-AA with Ferulic acid but the patent is very informative.
    I see these products with massive amounts of L-AA posted online a great deal. It puzzles me since I believe that a well-designed Formula meets the Cosmetic claims, usually with multiple complementing actives. A find the shotgun approach of “pack all the Vitamin C in you can” to miss opportunities such as this.
    My last impression is that I am curious to see what grade of Carbomer they successfully used. This Formula poses some challenges in that regard.
  • fromcstocs

    Member
    December 28, 2018 at 6:21 pm

    Thanks a lot for the answer. :) You are right, the Carbomer is also puzzling in a low pH formula. The lack of a base is also strange as 23% vitamin C is very acidic. Good to know that a more experienced formulator also finds these puzzling. :)  

  • MarkBroussard

    Member
    December 28, 2018 at 6:38 pm

    @fromcstocs:

    It would appear that they are using a pre-neutralized carbomer (note there is no TEA or NaOH base listed to neutralize the carbomer) and I suspect the Alkyl Benzoate is at a low percentage (1% or so) and they are just physically jamming the Alkyl Benzoate into the carbomer/sclerotium gum matrix.

    Not the most elegant approach. 

  • fromcstocs

    Member
    December 28, 2018 at 8:36 pm

    Thanks a lot!

  • Microformulation

    Member
    December 28, 2018 at 9:08 pm

    I had a line that attempted to incorporate lipids into such a matrix. They kept failing stability. I would be interested in testing a sample of this product to see if that is also an issue.

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