Home Cosmetic Science Talk Formulating Has Anyone Experienced Phase Inversion Issues with Sepinov WEO in O/W Emulsions?

  • Has Anyone Experienced Phase Inversion Issues with Sepinov WEO in O/W Emulsions?

    Posted by myungtaeberry on February 8, 2024 at 5:43 pm

    I’m in the midst of developing a buttery, balmy formula, and I’ve hit a bit of a snag related to stability. When I prepare my batches, everything seems fine until the temperature drops below 50 degrees. At this point, after adding thickeners, the mixture starts separating. Oddly enough, if I let it cool down and then quickly mix it by hand with a spatula, it returns to a normal state, and the stability isn’t compromised.

    Here’s what my formula looks like:

    • Water: 55%
    • Xanthan Gum: 0.1%
    • Emollients: 13%
    • Glyceryl Stearate: 1%
    • Polyglyceryl-3 Methylglucose Distearate: 3%
    • Bis-Diglyceryl Polyacyladipate-2: 6%
    • Polyhydroxystearic Acid: 0.5%
    • Shea Butter: 5%
    • Cetyl Alcohol: 0.5%
    • Sepiplus K: 0.5%
    • Sepinov EMT 10: 0.7%

    Post-emulsification, it looks okay, but after adding Sepinov WEO and homogenizing, it gets unstable at temperatures between 50-60 degrees Celsius.

    I’ve tried a few things like using different emulsifiers (Olivem 1000, Montanov 202, Sucrose Stearate, Sorbitan Sequioleate), but they either alter the texture or viscosity in ways that don’t work for me.

    Has anyone experienced something similar or have any insights? I’m looking for ways to solve this without changing the formula’s texture or viscosity too much.

    Thanks in advance for your help!

    myungtaeberry replied 2 weeks ago 3 Members · 4 Replies
  • 4 Replies
  • chemicalmatt

    February 13, 2024 at 2:29 pm

    Your addition of these Sepinov/Sepiplus acrylics is forcing this to be something it does not want to be: an o/w emulsion, thus the inversion. This would be very happy remaining w/o given your surfactant blend and oil load, but those darn acrylics…shame on them. DEL the SEPINOV and SEPIPLUS - and the xanthan while you are at it. Build viscosity and stabilize the external phase, which is lipid-based. Another glaring omission here: no polyol, needed when formulating with polyglyceryl fatty esters such as these. Throw in a little (not too much) propylene or butylene glycol, or…I hate to admit it: glycerin. I’d also consider adding a preservative as I do not see one present.

    • myungtaeberry

      February 17, 2024 at 8:46 pm

      Unfortunately, I can’t remove it. ;_;.. I guess too many thickeners cause instability in the formula.

      I didn’t know that the acrylic thickener causes phase inversion.

      The actual formula contains polyols and preservatives; I just didn’t mention it.

      Is there no solution other than removing Sepinov WEO and Sepiplus?

      • ChemistGuy

        February 17, 2024 at 10:42 pm

        How about this: Simple is better, get rid of all those emulsifiers and start over using one of the ones from Gattefosse (Emulium Kappa or Emulium Dolcea) at 5%. They are a blend of whatever you are already using. Keep trying.

        • myungtaeberry

          February 18, 2024 at 5:58 pm

          i will try it, thank you!

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