Home Cosmetic Science Talk Formulating Salicylic acid mild face wash

  • Salicylic acid mild face wash

    Posted by yyy on May 31, 2024 at 8:09 am

    Hi, i would like to get some advise on salicylic acid mild surfactant that I’m formulating. I am using thickener Acrylates/C10-30 Alkyl Acrylate Crosspolymer and xanthan gum as thickener to achieve slightly viscous texture. However, i noticed that two issues: not clear and undissolved particles like what we called fish eye.

    For the undissolved particles, im suspecting there is some reaction of Acrylates/C10-30 Alkyl Acrylate Crosspolymer and salicylic acid.

    Any advise how to solve the two issues? Thank you…


    Deionised water

    Trilon B

    Acrylates/C10-30 Alkyl Acrylate Crosspolymer

    Sodium cocoyl isethionate

    Salicylic Acid

    Glycerin

    Sodium Methyl cocoyl Taurate

    Xanthan Gum

    Cocamidopropyl Hydroxysultaine

    Polyquarternium-10

    PEG-6 Caprylic/Capric Glycerides

    Preservative MIT MCIT

    Zoya replied 3 weeks, 2 days ago 5 Members · 12 Replies
  • 12 Replies
  • evchem2

    Member
    June 3, 2024 at 7:39 am

    Is this your order of addition? I’d suggest getting the xanthan in earlier, right before or after the carbopol addition. You also have PQ-10 and combining cationic polymers with anioinics can cause precipitation/opacity. Also what is your final pH?

    • yyy

      Member
      June 4, 2024 at 10:09 am

      My end pH is around 4 to 5

  • Unknown Member

    Member
    June 3, 2024 at 8:01 pm

    I made a formula similar. modified cellulose plus acrylates copolymer and when I add salicylic acid and lactic acid, some gel-like particles will come out. and I add citric acid, it also precipate but after 0.5-1h

    stirring , all the particles can be dissovled.

    • yyy

      Member
      June 4, 2024 at 10:12 am

      Unfortunately in my case here, stirring doesnt help 😭

  • ketchito

    Member
    June 4, 2024 at 6:58 am

    Few things actually could be happening. First, Xanthan gum needs to also be hydrated before surfactants are added, with high mixing and for some time. Also, you’re not neutralizing your Acrylates…, so you won’t let it unfold and hydrate properly; plus, you won’t get viscosity from it at low pH. Also, your isethionate might not me stable for long at very low pH. Remove that Glycerin, please. And if you want to use Polyquaternium-10, mix it and hydrate it separately.

    • yyy

      Member
      June 4, 2024 at 10:14 am

      - The end pH of my formulation is pH 4 to 5, at this pH Isetionate is not stable at?

      - May i know the reason to remove Glycerin? Actually i will need it to hydrate the xanthan gum?

      • ketchito

        Member
        June 5, 2024 at 11:21 am

        As I recall, Sodium cocoyl isethionate being an ester, is prone to hydrolysis (especially acid). Below a pH of 6, this starts being an issue. Now, at a pH of 5 or close to 4, your acrylates are not properly neutralize so, you don’r have viscosity from this and it has reduced solubility. Even though glycerin helps de-agglomerate your xanthan gum before mixing with water, it can impair foam. Xanthan gum can be perfectly mixed in water, providing that you do it at the start. You actually don’t need these polymers in your system to get viscosity: isethionate is salt responsive, so add some Cocmidopropyl betaine and some salt (if you don’t want to add salt, add some Cocamide DEA or similar).

        • yyy

          Member
          June 8, 2024 at 1:33 am

          What will be the effects if hydrolysis of Sodium Cocoyl Isethionate ?

  • Unknown Member

    Member
    June 4, 2024 at 9:05 pm

    I made a similar thickening system using modified cellulose plus SF-1. are you sure the precipitation is from acrylates. In my system, what I found is if the pH below 4.8 or maybe 4.7 the both gel-like and white particles will precipitate which I think should be from acrylates and cellulose. but if the pH is above 4.8 there will be some gel-like particles only in the system and I think it is from cellulose. and I further found if you add salicylic acid or lactic acid, these gel-like particles can’t be dissolved. but if you use citric acid the gel-like particles can be dissolved after stirring.

    • yyy

      Member
      June 5, 2024 at 10:35 am

      Im not sure if it is caused by acrylates C10/30. Any advise which thickener is suitable to use in a salicylic acid mild surfactant cleanser?

      • Unknown Member

        Member
        June 10, 2024 at 7:56 pm

        non-ionic thickener

      • Zoya

        Member
        June 24, 2024 at 1:59 am

        in my experiences, for building viscosity of a Salicylic Acid system, the best option is xanthan gum. Most of the polymers and many of the gums don’t stand that low pH for a long time period. Also, if you increase the pH of your system, they wouldn’t stand the electrolytes. I’d skip the acrylate and use xanthan gum alone. I’d also change the isethionate to another surfactant that can stand low pH, as it’s usually not stable under pH 5.5, as mentioned above. Try something like sodium cocoyl glutamate, if you don’t mind that it can’t build viscosity with CAPB and salt, but can stand this low pH and can be paired with xanthan gum. You can also use Sodium Lauroyl Sarcosinate at this low pH or Glucosides combined with amphoterics.

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