Home Cosmetic Science Talk Formulating How much PROPYLENE GLYCOL to dissolve SALYCILIC ACID ?

  • How much PROPYLENE GLYCOL to dissolve SALYCILIC ACID ?

    Posted by Anonymous on August 6, 2016 at 1:33 am

    Hello everyone! I would like to  make a peel that contains Salycilic acid. I did research and found formulas (w/w???) that I frankly do not understand. How much propylene glycol(ml preferably)  do I need to dissolve 1g of Salycilic?
    I am trying to make a 15% peel

    Thanks in advance, 


    bobzchemist replied 7 years, 6 months ago 5 Members · 9 Replies
  • 9 Replies
  • microformulation

    August 6, 2016 at 10:27 am

    No offense, but if you are confused by Formulas that use wt/wt notation, you have a great deal to learn before attempting a dangerous product like a 15% peel! Please do not attempt this yet or hire a Consultant! This is a potentially dangerous product.

  • Anonymous

    August 6, 2016 at 6:36 pm

    I have been using that peel for many years and actually made it my self before. This timenthe powder I bought is not water soluble… That is why I need help figuring out how much PG I will need to completely dissolve the SA. I tried 2 days ago but it kind of crystallized. I guess I didn’t use enough PG. So my question is how much more should I use

  • microformulation

    August 6, 2016 at 8:34 pm

    Again, I do not feel comfortable assisting on such a dangerous product without someone having a strong Technical background. Wt/wt notation is basic. Understanding starting formulation is key.

  • belassi

    August 6, 2016 at 9:09 pm

    “this time the powder I bought is not water soluble”
    - why did you expect it to be? SA is not soluble in water. Did this not lead you to wonder just what on earth you were buying previously?

  • Anonymous

    August 6, 2016 at 10:34 pm


  • Christopher

    August 8, 2016 at 8:55 am

    I think you’re better off using multiple solvents instead of just one. I can’t tell you exactly how much PG you need for 1g of SA, but I’ve had success with dissolving 10 % SA in 75 % 1,3-propanediol and 15 % PG. Heating will probably be necessary. You would then add the remaining ingredients.
    But like everyone else here said, be careful!

  • Dilfre

    August 8, 2016 at 3:18 pm

    same problem arised two years ago in this forum.
    Hope it helps.

  • Anonymous

    August 10, 2016 at 9:38 pm

    Thank you everyone! 

  • bobzchemist

    August 11, 2016 at 1:48 pm

    I have to agree with Mark. If you can’t figure this out on your own, you should really stay far away from dangerous chemicals like this. 

    But…honestly, why aren’t you figuring this out experimentally? Start with 1 gram of SA and 2 grams of PG, and keep adding PG until soluble. The fact that you didn’t realize this was the fastest way to get your answer is yet another reason you shouldn’t be doing this yourself.

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