Home Cosmetic Science Talk Formulating cream cleanser with acid claim

  • cream cleanser with acid claim

    Posted by billichemist on April 9, 2015 at 3:10 am

    Following the advice of @makingcosmetics here is a new thread on my problem..

    I am formulating a cream cleansing lotion with a mixed fruit acids label claim. (ideally >5%)
    at the moment i have 2% acids in my formula but I can’t get it to pass accelerated stability (i assume the acids are causing the instability - liquid pools at the bottom of the container)
    here is my formula
    water - qs
    glycerine - 3.5
    decyl glcoside - 3
    steric acid - 3
    glyceryl stearate - 2.3
    cetyl alcohol - 7
    carnuba wax - 3.5
    avo oil - 3
    macadamia oil - 3.5
    alcoholic extracts - 3.5
    vit e - 0.2
    EO blend - 0.1
    xanthan gum - 0.05
    preservative 0.6
    mix fruit acids - 1
    lactic acid 44% 3
    is there something glaringly wrong with my formula that i cannot pick up??
    bobzchemist replied 8 years, 11 months ago 7 Members · 15 Replies
  • 15 Replies
  • MichelleReece

    Member
    April 9, 2015 at 6:36 am

    What preservative(s) are you using? Preservatives can conflict with and deactivate other ingredients.

  • billichemist

    Member
    April 9, 2015 at 7:42 am

    at the moment i am just using phenoxyethanol

  • bill_toge

    Member
    April 9, 2015 at 8:49 am

    even with the xanthan gum, your emulsifier (glyceryl stearate - I assume this is the SE grade) doesn’t seem robust for this type of product

    I suspect the decyl glucoside, i.e. a substantially water-soluble surfactant, and the lactic acid are competing with the emulsfier for the available water, and kicking it out of solution

    try adding an anionic emulsifier, e.g. Emulgade F or Crodafos CES, and see if that helps
  • AuroraBorealis

    Member
    April 9, 2015 at 1:43 pm

    Is this is a rinse off product? There’s quite a large amount of waxes and oils in there so I would blame this system for the instability more than the acids:

    steric acid - 3
    glyceryl stearate - 2.3
    cetyl alcohol - 7
    carnuba wax - 3.5
    avo oil - 3
    macadamia oil - 3.5
    If you must use that amount of waxes and oils try using a stronger (MUCH stronger) emulsifier system, pre solubilize your oils (polysorbates?) or just reduce the amount of waxes and oils. 
  • bobzchemist

    Member
    April 9, 2015 at 1:57 pm

    Also, Decyl Glucoside is a really bad emulsifier, to the point that it shouldn’t even be considered as part of the emulsification system.

    Have you made formulas with and without the acids? What were the stability results?
  • billichemist

    Member
    April 9, 2015 at 10:40 pm

    @bobzchemist : i’ve done centrifuge tests to give me an indication on how it would behave in stability and formulas without the acids pass centrifuge test while formulas with even the smallest amount of acids fail centrifuge tests (sedimentation of water)

    Decyl glycoside is for the cleansing/foaming properties.
    @auroraborealis and @Bill_Toge thank you for your suggestions, i will add an anionic emulsifier and reduce the oils. will let you know my results
  • chemist77

    Member
    April 10, 2015 at 2:22 am

    Try adding methocel, foam booster nd stabilizer.

  • billichemist

    Member
    April 10, 2015 at 2:56 am

    will sodium lauroyl lactylate be a suitable anionic emulsifier?

  • bobzchemist

    Member
    April 10, 2015 at 4:34 am

    Try it and see. It’s worth experimenting with multiple emulsifiers, just for your future knowledge.

  • billichemist

    Member
    April 15, 2015 at 1:17 am

    So i am back working on this… and I am so confused with my HLB numbers.. 

    I am experimenting with using blends of Glyceryl stearate and sodium lauroyl lactylate AND Glyceryl stearate and Potassium cetyl phosphate 

    I am trying to match the HLB emulsifuler values to the HLB oil values (right now its sitting at 10).. 
    1. i believe both SLL and PCP are co emulsifiers, for me to get the HLB values up to around 10, i will have to use a lot more of SLL or PCP than GS… is this correct?? i would assume as a co emulsifier you only need a small amount? but then the HLB Values don’t match.
    ahh!! 
  • bobzchemist

    Member
    April 15, 2015 at 3:38 am

    The lactylates don’t quite fit into the HLB system…

  • billichemist

    Member
    April 15, 2015 at 5:32 am

    ahh.. okay im completely taking GS out of the blend and using olivem 1000 instead… (So trialling a blend of Olivem1000 and Potassium cetyl phosphate)

    is GS even a main emulsifier? the HLB is so low! 
  • billichemist

    Member
    April 16, 2015 at 2:01 am

    So I made an emulsion with the following:

    water - qs
    glycerine - 3
    decyl glycoside -3
    potassium cetyl phosphate -1
    steric acid - 0.5
    olivem1000-5
    cetyl alcohol - 3
    carnuba wax - 0.5
    avocado oil- 3
    macadamia oil - 3
    Acids -10
    xanthan gum - 0.05
    preservative 0.6
    Misc extracts - 3.5
    a quick centrifuge test showed that it was not stable (I also did a test on the same cream without the acids and it showed to be stable in the centrifuge) 
    any other tips?? it also really thins out when i put the acids in
  • Ayla

    Member
    April 16, 2015 at 8:54 am

    Did you ask your supplier of Acids ?

  • bobzchemist

    Member
    April 16, 2015 at 2:22 pm

    Olivem needs to be at 8% or higher

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