Help with emulsion needed!

edited February 2014 in Formulating
I am formulating an emulsion with at least 10% of an ester.  The rest of the oil phase is about 20% (not including the ester).  I am using 4% cetyl alchol and 3% glyceryl stearate as the emulsifiers and stabilizing (tryig to ) the emulsion with carbomer.  The issue is that the ester continues to destabilize the emulsion and falls out.  Is this enough information to give me an idea of what to do?  Thanks for any help!

Comments

  • MakingSkincareMakingSkincare Member, Professional formulator
    edited February 2014
    Cetyl alcohol isn't really an emulsifier but it will help with stability and thickening. For an o/w emulsion, glyceryl stearate (presumably you have the non SE version) is a good low HLB emulsifier and ideally needs pairing up with a high HLB emulsifier (try at a total emulsifier blend of 7%, as 3% is too low).  Downloadable HLB calculator here - http://makingskincare.com/hlb-calculator/

    What other emulsifiers do you have available to you?
    Jane Barber
    www.makingskincare.com
    www.learncosmeticformulation.com (free online course)
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  • What is the name of the ester you are using?
  • chemicalmattchemicalmatt Member, Professional Chemist

    Dandy,

    With an oil load of 25 - 30%, you could get away with formulating without any GMS or cetyl, which by the way will not work here without a co-emulsifier of higher HLB (that's why so many supply the glyceryl stearate and PEG-150 searate combo), and just use Pemulen TR-2 polymeric emulsifier along with your Carbopol. No other emulsifer needed - just watch your electrolytes!

  • BobzchemistBobzchemist Member, PCF student
    I agree with Matt. If you aren't getting enough viscosity from the Pemulen, you can pair it with a small amount of Carbopol.
    Robert Zonis, Sr. Formulation Chemist, Beaumont Products "All opinions and comments expressed are my own, have no relation to Beaumont Products, are fully copyrighted, and may not be used without written permission."
  • Using a higher HLB emulsifier worked!  I had requested some previously, then came in this morning, and they were sitting on my desk.  I couldn't wait to try them out!  I have also requested a sample of the Pemulen TR-2, so I will evaluate that as well when it arrives.  Thanks everyone for the suggestions!

    The ester I am using is methyl salicylate for Mike, who requested that information.

  • MakingSkincareMakingSkincare Member, Professional formulator
    That's great, did you use a HLB calculator?
    Jane Barber
    www.makingskincare.com
    www.learncosmeticformulation.com (free online course)
    Formulation discussion forum (18,000 members): www.facebook.com/groups/makingskincare/
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