Home Cosmetic Science Talk Formulating solubility of salicylic acid in butylene glycol

  • solubility of salicylic acid in butylene glycol

    Posted by Nyatou on November 21, 2024 at 3:42 pm

    Hi to everybody,

    Does anybody know the solubility of Sa in butylene glycol?

    Nyatou replied 5 days, 3 hours ago 3 Members · 7 Replies
  • 7 Replies
  • Zoya

    Member
    November 22, 2024 at 9:01 am

    If you are using glycols, I would say 16-20* the quantity of the SA is generally a safe way to start experimenting, but it always depends on the other ingredients used in the formula, which can help SA stay in the solution , enabling you to reduce the amount of glycols.

  • Nyatou

    Member
    November 23, 2024 at 10:25 am

    Thank you. I have used successfully ratio 1:15 with propanediol. I wanted it to try with butylene glycol because I seen the combo sa +butylene a lot. Does anybody know what would be the advantages of butylene glycol over propanediol?

  • Nyatou

    Member
    November 26, 2024 at 1:13 pm

    @Zoya

    Any particular advice on the procedure? Sometimes I don’t know why I get crystalization. What I do is… I heat the SA with propanediol 1:15 ratio and then I mixed it with water and rest of ingredients.

    Regards.

    • Zoya

      Member
      November 28, 2024 at 5:22 am

      Hi.


      Increase the pH of the water phase with Sodium/Kalium Hydroxide or Sodium Citrate before adding the SA+propanediol mix. After adding the SA, the final pH should be ~3-4.

      • Nyatou

        Member
        November 28, 2024 at 2:13 pm

        Thank you so much!

    • fareloz

      Member
      November 28, 2024 at 5:40 am

      I heat the SA with propanediol 1:15 ratio and then I mixed it with water

      Solubility of SA is affected not only by amount of solubilizer, but other additions too. When you add water you decrease the solubility. When you have pure propanediol - you have very high solubility. When you have water+propanediol mix your solubility of SA in it is different. There is a whole study on how to calculate solubility in a mix of solvents: https://pubmed.ncbi.nlm.nih.gov/16649546/

      I wrote an article on reddit on how to formulate SA in DIY based on my experience, commercial products and studies. It also contains few formulas: https://www.reddit.com/r/DIYBeauty/comments/1d22zx8/formulation_guidelines_for_salicylic_acid_2_serum/

      • Nyatou

        Member
        November 28, 2024 at 2:16 pm

        Your article was very helpful. Thank you so much.

Log in to reply.

Chemists Corner