W/O lotion stability issue?

Dear experts,

I'm working with a w/o emulsifier called Neocare P3R to create a BB cream. 
I use 27% esters to have good spreadability and low viscosity. Although the emulsion looks good, after a few days it has this unhomogenous surface - that is disappearing after re-mixing, but coming back again after a while.

I read that it could be creaming, but I'm not sure what is causing it;
Mixing technique? 
Too much of the esters? 

If creaming, is there a way to fix it besides adding wax, which I find not ideal for the skinfeel?

Or if not creaming, what could it be?

Salt is added to the water phase, so that is not missing.

Thank you for any advice.

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Comments

  • PharmaPharma Member, Pharmacist
    W/O emulsions are a bit difficult and tend to break/sediment/cream.
    Could you give us a complete LOI and production procedure?
  • BettiBBettiB Member
    Sorry for asking back, but what does LOI stand for? Google was not helpful.

    I use Neocare in cold process. I add water phase drop by drop to the oil phase and slowly mix it after each addition. Afterwards, slowly mixing for 30 mins.

    This emulsifier does not like homogemization. 
  • AbdullahAbdullah Member
    List of ingredients with percentage of each
  • PharmaPharma Member, Pharmacist
    As @Abdullah said.
    You mix with what exactly?
  • BettiBBettiB Member
    Ah, ok. Thank you.

    1% MgSO4
    3% Glycerin
    0.1% chelator
    1% Preservative
    Up to 100% water

    27% coco-caprylate
    2% jojoba
    2% iron oxide (mix)
    0.3% glyceryl caprylate 
    4% neocare p3r

    Mixing with magnetic stirrer at around 200 rpm. 
  • PharmaPharma Member, Pharmacist
    Astonishingly, you somehow managed to get an emulsion with a magnetic stirring bar... that's something. Although, I would say the emulsion is not fine enough and you need more than just a magnetic stirrer, a lot more actually, at least something with a propeller but I think you'd still have to give it a quick spin with a homogeniser at the end. Should work well with PGPR, just don't overdo that step.
    Further considerations:
    - GMCY as preservative at that rate would be more efficient if incorporated into the water phase or, if used as co-emulsifier, requires higher levels (though in that case, a different product would be my pick).
    - Your oil phase is very low viscosity; a wax, hydrogenated oil, butter, or any other type of oil gellant would really be a good thing in the order of 'you can't do without'.
    - You could try to gel the water phase... can't remember who it was here on board claiming that this is actually a bad idea (sadly, I don't remember him/her explaining why water gelling in a w/o emulsion is prone to failure).
    - First try without iron oxide until you get a stable product.
  • BettiBBettiB Member
    Thanks for your detailed answer. Really appreciate it. 

    What would you use insetad of GMCY? I read that in the water phase it needs a solubilizer, that is why it was added to the oil phase. 

    I was thinking of adding magnesium stearate at 0.3% to the oils, I would like to avoid wax or butter. I feel like the skin is sweating under.

    Gelling water with a gum, you mean?

    Thank you. 
  • PharmaPharma Member, Pharmacist
    Depends on what GMCY should do. If it's as preservative, it's dispersable in water and, according to theory, will lose in activity if brought into solution with the aid of an emulsifier... Do you cold or hot process?

    You can try gelling the oil phase simply by preparing the oil phase alone, let it cool, and see/feel how viscous it gets and at which temp it melts. Gelling oil is seldom like gelling water (although there are a few polymers which work) but more often involves high melting stuff like waxes or saturated fatty acids. Sure, try magnesium stearate (and don't forget to adjust your pH if need be).
    It's a w/o emulsion, sweating underneath is part of the deal, if you will. Switching PGPR for more modern and more robust emulsifiers like Isolan GPS allows for the preparation of HIPE gels (PGPR is said to work too but I have my doubts that you'll manage to easily produce something stable) which contain less than 20% oil and are therefore less occlusive.
  • BettiBBettiB Member
    Thanks for your recommendations.

    I have not experienced sweating if there was no wax, butter added. I actually find Neocare a fab emulsifier for gorgeous velvety skinfeel. It seems that I managed to fix this issue with proper mixing. Centrifugal test showed no stability issue. Another one follows in a week.

    I will also check Isolan GPS. Thanks.

    Just one last question; adjusting ph after adding Mg Stearate? I would add it to the oils, and I adjust the ph of the water phase before emulsification. Can you please let me know what you meant related to Mg Stearate? Thank you.
  • BettiBBettiB Member
    Ah, sorry, I missed answering on your question. I use cold process. I add preservative eco 1388 to the water phase. Here is the producer's reco in case of this combination with GMCY. "Note: In Combination with dermosoft® 1388 / anisate or alkaline presolutions, addition to the oil phase is recommended."
  • PharmaPharma Member, Pharmacist
    Cold process, that limits things. How do you get GMCY to dissolve in the oil phase without heat?
    Assuming you are using 1388: You have to adjust pH to slightly acidic for it to work.
    I wasn't referring to Mg stearate when mentioning pH, I just realised that you should adjust pH, poor choice of formulation myself, sorry. pH is mostly so that certain preservatives like 1388 can work.
  • BettiBBettiB Member
    GMCY is dissolving at 30C degree. I just need a slight heating, but emulsification is on RT.

    Yes, ph is adjusted to 5.0.

    Thanks for all your help 👍
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