Home Cosmetic Science Talk Formulating Understanding pH Buffers & pH Adjustments in Skin Care Formulations

  • Understanding pH Buffers & pH Adjustments in Skin Care Formulations

    Posted by JSharp93 on April 29, 2020 at 12:53 pm

    Hello Everone,

    I trust you are all well and keeping safe during these uncertain times.

    Having had more spare time on my hand I have decided to revisit my old notes taken during my Cosmetic Science Diploma, in the attempt to better understand cosmetic formulation.

    I am trying to understand how to go about stabilising the pH of a skin care formulation. From my old reference books I understand that one would use a pH Buffer to stabilise and maintain a products pH. These buffers consist of an acid such as Citric Acid and a corresponding base; in the case of Citric Acid you would use Sodium Citrate. My question is how, would you go about formulating with a buffer? Is there a set % you would require to use in order to have a obtain the desired pH? At what stage would you add the pH buffer?

    For example, if I was formulating a Toner product that requires a final pH of 5.5 how might I go about achieving this pH and how might I stabilise said pH?

    Apologies for all the questions but any help would be much appreciated.

    JSharp93 replied 3 years, 11 months ago 2 Members · 2 Replies
  • 2 Replies
  • EVchem

    April 29, 2020 at 5:56 pm

    There was a very recent post on this topic 

    Basically if you know what pH you want your formula to be you can select a buffer that has a range encompassing your selected pH. Citric acid should be fine for 5.5, and with a little base (sodium hydroxide would work well) you can create the sodium citrate in situ.  

    So make your toner and adjust pH at the end using a combination of your acid and base. You would then check the sample over a period of time to see if the buffer remains effective

  • JSharp93

    April 30, 2020 at 2:00 pm

    Thank you very much for your help EVchem.

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