Sodium ascrobyl phosphate Ph Adjustment

I am trying to make 5% Sodium ascrobyl phosphate serum in water and ph comes around 9 
I am using Citric acid solution to lower the ph
But citric acid has some peeling properties
Is there a ph ph adjuster which i can use which is more gentle and soothing for skin?
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Comments

  • ngarayeva001ngarayeva001 Member
    edited April 9
    pH is a quantitative measurement of acidity and acidity is a qualitative measurement of acidic properties of a solution. Citric acid is an AHA but it won’t do anything under a neutral pH, which is what, I believe, you are trying to achieve.
  • GuntherGunther Member
    If your final pH ain't too acidic, you won't have any (or just very little) free citric acid left, as all of it will be used up to neutralize whatever is making the Sodium ascorbyl phosphate alkaline.
    All (or most) citric acid will react to become a much milder citrate salt.
  • MarkBroussardMarkBroussard Member, Professional Chemist
    Phytic Acid would work for this purpose
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    Provides Formulation Development and Lab-Scale Contract Manufacturing Services.  See website for details www.desertinbloomcosmeticslab.com

  • ThotaThota Member
    What preservative are using?
    I am making SAP serum and using lactic acid to bring the ph to 6.5
    And I used to use PE 9010 but now am searching hard to replace it. 
    Will Sodium Benzoate work at pH 6.5?
    What preservative will work for something at this pH?
  • @Thota I agree with @Microformulation use Sodium Phytate and yes I believe you can use Sodium Benzoate but you need to adjust the pH down. What ingredient is making it so high?
    Dr. Catherine Pratt
    (B.Sc with HONS I , Ph.D Analytical/Organic Chem and Microbiology), Cosmetic Chemistry IPCS)
  • ThotaThota Member
    @Thota I agree with @Microformulation use Sodium Phytate and yes I believe you can use Sodium Benzoate but you need to adjust the pH down. What ingredient is making it so high?
    @ Dr Catherine sodium ascorbyl phosphate seems to cause discoloration at pH below 6 and the supplier mentions that its most stable at pH 6.5-7

    Also wanted to know if there is any problem with LA to bring down the pH. I dont have sodium phytate at hand.
  • Citric Acid - use 50%
    Dr. Catherine Pratt
    (B.Sc with HONS I , Ph.D Analytical/Organic Chem and Microbiology), Cosmetic Chemistry IPCS)
  • DoreenDoreen Member
    edited April 18
    @Dr Catherine Pratt
    It's the Sodium Ascorbyl Phosphate that is alkaline, and I'm not surprised that a 5% solution will make a pH of around 9. 
    I recently formulated a moisturizer with 3% SAP and I thought I would need something like sodium lactate to raise the pH some more to 6.5, but I even needed to lower the pH (it was 8.12).

    @Thota
    I think the discoloration you mention below pH 6 is actually the SAP oxidizing. 
    You wanted to change preservatives because of skin reactions due to phenoxyethanol, right? How about Liquid Germall Plus? Or Germaben II?

    @Waleed636
    I used lactic acid to lower the pH a bit.
  • #Doreen, yes you are correct, I recently used this chemical and I used 0.3% to 0.4%. I then used a buffer.
    As far as the preservative, maybe you could try Geoguard ECT, it has wide pH capability, cheap and only small amounts are needed in the formula.
    Hope this helps?
    Dr. Catherine Pratt
    (B.Sc with HONS I , Ph.D Analytical/Organic Chem and Microbiology), Cosmetic Chemistry IPCS)
  • bil7bil7 Member
    You can use lactic acid best with sodium ascorbyl phosphate or sodium citrate as milder one
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