Home Cosmetic Science Talk Formulating Stabilizing surfactants in an anhydrous emulsion

  • Stabilizing surfactants in an anhydrous emulsion

    Posted by seaberry on June 28, 2021 at 7:49 pm

    Hello all! I’d like to ask for some ideas on this cleanser I’m working on, which contains sodium cocoyl isethionate in a glycerin and oil emulsion. 

    The formula is basically
    40% oil
    40% glycerin
    10% montanov 68mb
    5% polyglyceryl-3 cocoate
    5% sodium cocoyl isethionate

    The formula comes together well, but white blobs of surfactant separate out very quickly. It stays together for about a minute when shaken vigorously. The emulsion is completely stable when made without the SCI.

    I know SCI is generally solubilized into an amphoteric like CMPB, but I find that SCI is easily stabilized with standard emulsifiers in general. It’s just here that it won’t stay homogeneous.

    Any tips on getting this stable? Thanks.

    seaberry replied 2 years, 9 months ago 4 Members · 6 Replies
  • 6 Replies
  • Mic001

    Member
    June 29, 2021 at 1:00 pm

    what is the pupose of the formula? Seems like it might be a polarity issue. 

  • seaberry

    Member
    June 29, 2021 at 1:59 pm

    Mic001 said:

    what is the pupose of the formula? Seems like it might be a polarity issue. 

    The goal is a makeup remover that rinses cleanly. 

    Hm, I thought polyglycerin esters were non-ionic, which should play well with anionic SCI, right?

  • chemicalmatt

    Member
    June 30, 2021 at 9:14 pm

    @seaberry I may be stating the obvious here: DEL the SCI altogether. The oil component (identity?) is doing the heavy lifting in makeup removal, your surfactants are mainly employed to remove both oil solvent and makeup. Why not select another nonionic surfactant to solvate/remove the collective crud or just q.s. with the glyceryl ester?

  • seaberry

    Member
    July 1, 2021 at 3:42 pm

    @seaberry I may be stating the obvious here: DEL the SCI altogether. The oil component (identity?) is doing the heavy lifting in makeup removal, your surfactants are mainly employed to remove both oil solvent and makeup. Why not select another nonionic surfactant to solvate/remove the collective crud or just q.s. with the glyceryl ester?

    That does seem like a good idea. You’re absolutely right about the oil (I’ve been using ethylhexyl palmitate or safflower oil for testing) solubilizing the makeup, and then the surfactant to rinse everything away. 

    The makeup melting works fine, but I’d prefer a cleaner rinse. The above formula with extra glyceryl ester in place of SCI leaves a thick, waxy film on the face, unfortunately. 

    What surfactants would you consider for this purpose? I understand most standard non-ionics include water and would thus necessitate a preservative. 

  • ozgirl

    Member
    July 1, 2021 at 10:20 pm

    I remember this similar type of formula from Innospec https://personalcaremagazine.com/formulation-details/2564/bubble-scrub-butter where it required the addition of sodium chloride. Not sure if that would help in this case but it might be worth a try.

  • seaberry

    Member
    July 2, 2021 at 12:32 am

    ozgirl said:

    I remember this similar type of formula from Innospec https://personalcaremagazine.com/formulation-details/2564/bubble-scrub-butter where it required the addition of sodium chloride. Not sure if that would help in this case but it might be worth a try.

    That is very interesting formula. If I understand correctly, that’s 50% oil “emulsified” by ~40% surfactant and thickened by NaCl, which is wild. I’m gonna have to take a deeper look at this for sure. Thanks for sharing! 

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