Formula turning white when rubbed into the skin after changing emulsifier, how to solve?

We switched the emulsifier from Ewax (which rubs in nicely, but doesn't do great with very thin lotions) to Glyceryl Stearate & PEG-100 Stearate (Lotioncrafter 165) which is better for thin lotions, but now we have a rub in problem; the formula turns white when rubbed in and takes 3x longer to disappear into the skin.

Glycolic Acid 5%
Sodium PCA
Sodium Hydroxide
Allantoin
Glycerin
Sclerotium Gum 0.5%
Glyceryl Stearate PEG-100 Stearate
Cetyl Alcohol
Simmondsia Chinensis (Jojoba) Seed Oil
Stearic Acid
Phenoxyethanol, Caprylyl Glycol, Sorbic Acid

Suspect it might be an interaction between the gum and the emulsifier? It's often used in AHA formulas that have no issues with rub-in (for example the one from Acne.org). 

What do you think is causing it and how to prevent it?





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Comments

  • It's not the emulsifier, it's the stearic acid. Is the emulsifier the only variable? It's surprising it didn't soap before. The fix is super easy though - add dimethicone.
  • Yep, your'e probably going to say to you want to avoid or not use it but the simplest answer is dimethicone. Its the magic potion.
  • ngarayeva001 in that case it would be the emulsifier combined with stearic acid as we didn't have the issue using stearic acid + ewax.

    @crillz you're right and I realize that "soaping" is the term for what I want to avoid, in another thread from 2014 some alternatives to dimethicone were proposed https://chemistscorner.com/cosmeticsciencetalk/discussion/781/natural-anti-soaping-whitening-effect-ingredients

    2% CPS1000 dimethicone does indeed cut soaping in half or so, but Dicaprylyl Ether and Isoamyl Laurate was proposed as natural alternatives. Wondering if DOW 1400 or 1401 could work even better than dimethicone also.

    Things to try:
    1. Remove stearic acid
    2. Try a different gelling agent
    3. Add 2% dimethicone CPS1000
    4. Add 4% Dicaprylyl Ether or Isoamyl Laurate.


  • Another option could be Plantasens Olive LD, which reportedly reduces soaping.

    Personally, I'd go with 5-20 cst dimethicone.
  • Bill_TogeBill_Toge Member, Professional Chemist
    what's the percentage of jojoba oil?
    UK based formulation chemist. Strongest subjects: hair styling, hair bleaches, hair dyes (oxidative and non-oxidative) I know some stuff about: EU regulations, emulsions (O/W and W/O), toothpaste, mouthwash, shampoos, other toiletries
  • Thanks Vnnil. Why not higher cst? 1000 cst seems to work fine.

    Bill: 5% Jojoba.
  • It's easier to emulsify and won't change the feel as much as the 1000 cst.

    You could also blend them, depending on the sensorials you're aiming for.

  • It really depends on the formula. I can notice a difference in a lower viscosity gel cream formulas made with light esters but not in more traditional thicker creams. I would not be able to tell a difference between dimethicone 1000 and dimethicone 10 in a cream like the one above. And since 1000 is cheaper and easier to find I would use 1000. Also arlacel 165 will emulsify small amount of silicone easily no matter what the viscosity is.
  • Vnnil said:
    Another option could be Plantasens Olive LD, which reportedly reduces soaping.

    Personally, I'd go with 5-20 cst dimethicone.
    I do have this silicone replacement but I find Gosulin IL( Isoamyl Laurate, Isoamyl Cocoate ) works better regarding whitening and spreading. 
  • @antmagn how much Gosulin IL did you use to reduce whitening?
  • Tried em all, dimethicone is 3x as good as the second best option.
  • Have you tried with isomyl laurate? Mind sharing the outcome?
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