Home Cosmetic Science Talk Formulating Improve the stability of Ewax based emulsion with co-emulsifiers?

  • Improve the stability of Ewax based emulsion with co-emulsifiers?

    Posted by Zink on October 29, 2014 at 9:38 pm

    As discussed in previous threads I’ve been experimenting with an HLB 8 oil in water emulsion containing benzoyl peroxide, which destabilizes it. Two emulsifiers I’ve tested:


    Lotionpro165:     Glyceryl Stearate (and) PEG 100 Stearate, is stable without any additional thickeners.
    Ewax:               Cetearyl Alcohol (and) Polysorbate 60, separates after a couple of days at 42C.

    I’d use lotionpro if it wasn’t for it’s extremely poor absorption, and I don’t want to use gums as they lead to the same issue.  Could it work to improve the stability of the ewax formula by adding a low HLB emulsifier? E.g. Glycol Distearate (HLB 1), Glyceryl Stearate (HLB 3.8) or Steareth-2 (HLB 4.9)?

    Or even a pre mixed emulsifier blend such as Polyacrylate 13, Polyisobutene, Polysorbate 20 (Sepiplus 400) or

    Acrylates/C10-30 alkyl acrylate crosspolymer (Pemulen TR2)?

    Zink replied 9 years, 6 months ago 1 Member · 1 Reply
  • 1 Reply
  • Zink

    Member
    October 29, 2014 at 9:55 pm

    An interesting example is from Neutrogena on the spot, HLB values in ().

    Active: Benzoyl Peroxide (2.5%), Other: Water, Bentonite, Caprylic/Capric Triglyceride (11), Glycerin, Emulsifying Wax Nf, Polysorbate 20 (16.7), Glyceryl Laurate (5.2), Cetyl Dimethicone, Magnesium Aluminum Silicate, Xanthan Gum, Sodium Citrate, Disodium EDTA, Citric Acid, Methylparaben, Propylparaben.  

    They’ve gone a long way to make sure their formula is stable, using two extra co-emulsifiers and two thickeners.

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