Home Cosmetic Science Talk Formulating Chelating agents with Glyceryl Stearate; is EDTA Failing Emulsions?

  • Chelating agents with Glyceryl Stearate; is EDTA Failing Emulsions?

    Posted by Transformize on October 29, 2023 at 11:01 am

    I’m starting to work with ceteareth-25 and glyceryl stearate as my emulsifiers, added to the cetearyl alcohol. I’ve read, so is it true, that EDTA’s are not compatible with glyceryl stearate? I’m using the standard glyceryl stearate, not the SE, or Citrate versions. Every lotion that I have made with disodium EDTA and these two emulsifiers has separated within 1 day. And, two lotions that I made without the Disodium EDTA has not separated yet, and it’s been 3 days?
    If this is true, can anyone suggest some compatible chelating agents?

    My body lotion ingredients:
    Water Phase: Water, Glycerin, Hydroxyethylcellulose (HEC), Disodium EDTA
    Oil Phase: Caprylic/Capric, Cetyl Alcohol, Shea Butter, Stearic Acid,
    Cetearyl Alcohol, Ceteareth-25, Glyceryl Stearate
    Cooling Stage: Fragrance, Phenoxyethanol, Benzyl Alcohol, Ethylhexylglycerin

    Thanks for your help.


    chemicalmatt replied 7 months, 2 weeks ago 4 Members · 5 Replies
  • 5 Replies
  • Transformize

    Member
    October 29, 2023 at 1:23 pm

    I also didn’t want it to thin the lotion.

  • suswang8

    Member
    November 2, 2023 at 6:18 pm

    Did you already try sodium phytate? Or can that not be used for some reason?

  • Transformize

    Member
    November 2, 2023 at 6:22 pm

    I already have sodium phytate in my cart, towards my next order. I just didn’t know if it was the disodium EDTA with the glyceryl stearate. I’ve also thought about sodium citrate.

    • This reply was modified 7 months, 2 weeks ago by  Transformize.
  • ketchito

    Member
    November 2, 2023 at 9:02 pm

    Glyceryl stearate is an ester (non ionic), so there shouldn’t be an issue with EDTA. Now, what could be happening is that if you use dissodium EDTA, the final pH is lower and most of your Stearic acid is in the acid form (when neutralized, Stearic acid works as an emulsifier). That’s why you have a thicker product without EDTA. Just a guess.

  • chemicalmatt

    Member
    November 3, 2023 at 10:33 am

    Adding to @ketchito here, all correct, but here is a bit of tribal knowledge to consider here (I just have to begin charging money for this): your viscosity problem is not related to GMS or Stearac at all but hydroxyethylcellulose. Disodium EDTA will impede hydration-gelation of HEC, especially the cationic type. I found this out one day when I added EDTA to water first then dispersed Ucare Polymer JR-30M. After two hours the polymer still had not hydrated and I knew that should have only taken 20 minutes. I retried only this time leaving out the EDTA until the cationic HEC was fully hydrated and no problem. Try altering order of addition and see what happens. You do need to add a small amount of alkali to fully hydrate HEC depending on the grade and I don’t see that mentioned in Part A - or anywhere else. How does stearic acid make any sense without TEA, AMP or TrisAmino to saponify with? Could be part of the problem too.

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