Home Cosmetic Science Talk Formulating Surfactants for AHA cleanser

  • Surfactants for AHA cleanser

    Posted by Storm on October 29, 2020 at 3:06 am

    Hi fellow formulators

    I’m having trouble choosing the right surfactants for a gentle AHA cleanser, pH=4.5, sulfate free.
    Below is what I have tested so far;
    1- 10% Sodium Cocoyl Glutamate (Plantapon ACG HC) in water
    - Reducing the pH to 5.0 using Lactic Acid, completely opaque, viscosity broke, after 5 minutes sitting without mixing, turned to an opaque gel.
    2- 10% Disodium Cocoamphodiacetate (Dehyton DC-AS) in water
    - Reducing the pH to 5.8 using Lactic Acid, completely opaque
    3- 10% Sodium Lauramphodiacetate in water
    - Reducing the pH to 4.5 using Lactic Acid, clear no sediment
    4- 10% Coco Glucoside or 10% Caprylyl/Capryl Glucoside in water
    - Reducing the pH to 4 using Lactic Acid, they both stay clear with no sediments.
    My questions are:
    - What is the best Anionic surfactant (sulfate free) option for pH around 4.5?
    - Why Cocoamphodiacetate is unstable at low pH while Lauramphodiacetate is stable?
    - Between Coco Glucoside and Caprylyl/Capryl Glucoside, which one has a better foam and milder?
    - Is there a source to compare surfactants mildness, foam and pH stability?
    Thanks for reading this long post and hope to hear your thoughts.
    Storm replied 3 years, 4 months ago 4 Members · 6 Replies
  • 6 Replies
  • melindanicole

    Member
    October 30, 2020 at 2:49 pm

    What about Sodium C14-16 Olefin Sulfonate and cocoamidopropyl betaine? Here is a neat chart of sulfate free surfactants with details, off of Making Skincare https://makingskincare.com/sulfate-free-surfactants/

  • Agate

    Member
    October 31, 2020 at 4:44 pm

    Can’t answer all the questions, but from my experience I haven’t noticed a difference between Coco Glucoside and Caprylyl/Capryl Glucoside in mildness or foam. The main difference that I’ve seen is that Coco Glucoside is cheaper but Capryl/Caprylyl Glucoside works better as a solubilizer.

  • Storm

    Member
    November 2, 2020 at 11:35 pm

    What about Sodium C14-16 Olefin Sulfonate and cocoamidopropyl betaine? Here is a neat chart of sulfate free surfactants with details, off of Making Skincare https://makingskincare.com/sulfate-free-surfactants/

    What a useful chart, thanks for sharing Melinda.
    I don’t have access to small quantities of Sodium C14-16 Olefin Sulfonate but form the chart Pureact LSR (Sodium Lauroyl Sarcosinate) seems to be another option.
    Not sure if Sodium Lauroyl Sarcosinate can be used as primary surfactant though? have you worked with this one before?

  • Storm

    Member
    November 2, 2020 at 11:36 pm

    Agate said:

    Can’t answer all the questions, but from my experience I haven’t noticed a difference between Coco Glucoside and Caprylyl/Capryl Glucoside in mildness or foam. The main difference that I’ve seen is that Coco Glucoside is cheaper but Capryl/Caprylyl Glucoside works better as a solubilizer.

    Thanks Agate for the comment. How does Decyl Glucoside compare with the other two?

  • chemist1

    Member
    November 4, 2020 at 9:26 pm

    Pureact WS Conc-Sodium Methyl Cocoyl Taurate would be a perfect surfactant for this type of application. 

  • Storm

    Member
    November 6, 2020 at 5:53 am

    chemist1 said:

    Pureact WS Conc-Sodium Methyl Cocoyl Taurate would be a perfect surfactant for this type of application. 

    Thanks for the suggestion Chemist1. I’ll give it a try.
    I’m wondering at pH=4.5 do I need to include an amphoteric? Chemically speaking it will turn to a cationic at that pH right? Wondering if that will be incompatible with the rest of ingredients!

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