Home Cosmetic Science Talk Formulating Refrigeration of Vitamin C Serum: Yes or no?

  • Refrigeration of Vitamin C Serum: Yes or no?

    Posted by ETcellphone on March 4, 2021 at 3:18 am

    From what I hear, keeping your vitamin C serum in a cold, dark environment like a refrigerator is a good idea to keep it fresh and potent longer. 

    Would you agree with this idea?

    Why do I ask? It gets a crusty residue inside the bottle.
    Here is what i have noticed: I have been keeping mine in a small dropper bottle in the fridge. When I do this, I notice that the glass on the interior of the bottle gets a patchy, crusty residue which I assume is at least part L-Ascorbic acid and tocopherol. Also, when I unscrew the dropper and lift it out of the bottle, the glass tube connected to the rubber dropper is also encrusted with some of the same residue. Is putting it in the refrigerator messing up my serum? Is it separating my ingredients? 

    Also, if I were to keep taking it in and out of the fridge, do you think this daily temperature fluctuation, from cold to room temperature and then back to cold again, could hurt the actives in my serum? I only have it out of the fridge for maximum 30 minutes. 

    Here is the vitamin C serum formula:
    - Distilled water- 72%
    - L-Ascorbic acid- 15%
    - Sodium lactate- 2%
    - Ferulic acid- 0.5%
    -Propylene glycol- 7%
    - Tocopherol- 1%
    - Polysorbate 80- 1%
    - Optiphen- 1%
    - Xanthan Gum- 0.5% (I just tried this in my newest batch, which I haven’t refrigerated yet) 

    Should I keep it in my dresser from now, instead of the refrigerator? 

    Also, any critiques of this formula I am happy to hear. 

    Paprik replied 3 years, 6 months ago 7 Members · 9 Replies
  • 9 Replies
  • Pattsi

    Member
    March 4, 2021 at 9:53 am

    Your main solvent is water, when water evaporated L-Ascorbic acid would recrystallize.
    Maybe try adjust you glycol.

    Also, if I were to keep taking it in and out of the fridge, do you think this daily temperature fluctuation, from cold to room temperature and then back to cold again, could hurt the actives in my serum? I only have it out of the fridge for maximum 30 minutes. 

    If it was me I would not concern much since DIY L-Ascorbic acid- 15% serum has a very short shelf life maybe 3 - 7 days.

  • Bill_Toge

    Member
    March 4, 2021 at 7:08 pm
    to my mind it’s most likely the ferulic acid or the vitamin E; they’re the least water-soluble components
    I’d suggest using a more powerful antioxidant like sodium bisulphite, combined with an excited-state quencher like benzophenone-4 to keep the amount of reactive oxygen to a minimum
  • ETcellphone

    Member
    March 5, 2021 at 4:10 am

    Pattsi said:

    Your main solvent is water, when water evaporated L-Ascorbic acid would recrystallize.
    Maybe try adjust you glycol.

    Also, if I were to keep taking it in and out of the fridge, do you think this daily temperature fluctuation, from cold to room temperature and then back to cold again, could hurt the actives in my serum? I only have it out of the fridge for maximum 30 minutes. 

    If it was me I would not concern much since DIY L-Ascorbic acid- 15% serum has a very short shelf life maybe 3 - 7 days.

    Thanks Pattsi. Do you think even a formula like the one I listed would lose its potency after 3-7 days? Would you say the same thing about the near $200 cult product Skinceuticals CE+Ferulic serum? Is there no way to stop this from happening, in your opinion? 

    Skinceuticals CE+Ferulic serum ingredients: 
    Aqua/Water/Eau, Ethoxydiglycol, Ascorbic Acid, Glycerin, Propylene Glycol, Laureth-23, Phenoxyethanol, Tocopherol, Triethanolamine, Ferulic Acid, Panthenol, Sodium Hyaluronate.

  • ETcellphone

    Member
    March 5, 2021 at 4:11 am

    Bill_Toge said:

    to my mind it’s most likely the ferulic acid or the vitamin E; they’re the least water-soluble components
    I’d suggest using a more powerful antioxidant like sodium bisulphite, combined with an excited-state quencher like benzophenone-4 to keep the amount of reactive oxygen to a minimum

    thanks Bill. I will look into these ingredients you recommended. 

  • Pattsi

    Member
    March 5, 2021 at 7:35 am

    Skinceuticals CE+Ferulic serum - would last longer than 3-7 days as they studied and stated in their patent. But IMHO it can’t be 1-2 years.

    Skinceuticals CE+Ferulic serum ingredients: 
    Aqua/Water/Eau, Ethoxydiglycol, Ascorbic Acid, Glycerin, Propylene Glycol, Laureth-23, Phenoxyethanol, Tocopherol, Triethanolamine, Ferulic Acid, Panthenol, Sodium Hyaluronate.

  • Andraous

    Member
    April 30, 2021 at 6:03 pm

    Dears

    This formula needs UV filtration 

  • ngarayeva001

    Member
    April 30, 2021 at 7:16 pm

    Even the Skinceuticals CE Ferulic oxidizes. Maybe slower than all other LAA serums but it still does.

  • OldPerry

    Member
    April 30, 2021 at 8:45 pm

    I’d say don’t bother with refrigeration.

    It’s unlikely you will be able to detect any differences in performance between a product that was refrigerated and one that wasn’t.

    The main questions to ask yourself is how can you tell that the serum is “potent” at all? What are the measurable benefits that you have experienced?

    Does it really matter how fast it oxidizes or how “potent” it is if you can’t actually notice any difference?

  • Paprik

    Member
    May 3, 2021 at 3:20 am

    If I can add .. what’s the final pH? 
    Keep it around 3.5 for best results.
    How fast does it turn pale yellow [in days]?

    I keep my serum in bathroom and am making a new one every 2 - 3 weeks. Going to fridge for it everytime would be super annoying. :D 

    Also, in my opinion, you don’t have enough solubiliser. You have 1% Polysorbate 80 for 1% Tocopherol. Although, I’ve never worked with that material, so can’t tell for sure. 
    Method is crucial, do you solubilize the Toco properly before adding into water? Does it go clear before each adding? 

    And curiosity question: Do you like it with the Xanthan Gum? I’m thickening it up with a bit of HA to get the slip. Probably depending on what grade of XG you’re using, but it may feel sticky? 

Log in to reply.

Chemists Corner