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Foundation (w/si) viscosity issue
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I did some thinking, some reading, some more thinking and reading…It looks like a tough nut to crack and that’s what intrigues me though it’s hard work. See, what we learn in galenics is o/w emulsions and their laws. Hence, these come natural to me which is quite the nuisance when thinking about inverse emulsions such as w/o or w/si. That’s because half the laws don’t apply and the other half, though still following the same rules, results in completely different effects. In addition to that, you get the same effects with different approaches in the two emulsion types. On the other hand, most w/o emulsions aren’t of the droplet-type but lamellar or 3D-networks.That said, there might be some misconceptions in my first brain churning approach, who knows? For example, removing electrolytes might shift the droplet-type emulsion to a worm-like structure which can as well result in an emulsion of higher viscosity, not the other way round.I’ve been thinking about triple ratio of non-ionic surfactant/anionic surfactant/fatty alcohol, surface shape of these molecules, surface charge aka zeta potential etc. The one thing all comes down to seems to be charge related. Somehow the custom pigments annihilate negative surface charge although in a w/si emulsion, there is only a charged inner surface, not an outer one. Hmmm….It might be advisable to re-start from the beginning, figuring out a simple, easy, and cheap solution:- “Your supplier said…” does that mean you have a basic formulation you improved over time? What would the most reductionistic formula (w/o pigments) which is still stable and viscous be?- Did you find out what’s in that custom blend? Do they use quats?- What’s the highest amount of custom blend you can add before emulsion tips over?- The below 40°C homogenisation, is that also low shear?- Do you know for sure it’s a w/si emulsion?- Don’t throw your failures away! Try for example adding an anionic high HLB emulsifier at 0,2% (guessing here), just something on your shelf such as glyceryl stearate citrate. Even an anionic detergent like SLS, SLES, an isethionate, or a lactylate might work. If they work: your issue is most likely charge related and hence solvable.Gotta go for now (it’s getting less hot and the doggies need their party). -
Thank you @Pharma. I will try to add glyceryl stearate SE for the anionic. Regarding your questions, I think it should be w/si because I use w/si emulsifier but I know chemistry doest always work this way.
I can add up to 10% of the custom blend before it breaks. The blend is iron oxides and TiO2 in octyldodecanol. The below 40 homogenisation is a stick blender (I process the emulsion on the overhead stirrer). Without pigments the emulsion is liquid and gets the viscosity ones I apply stick blender.
I continue working on it and ordered more ingredients for making foundations recently. Hopefully I will get there at some point 🙂
I wonder if there are any more or less simplified materials about making w/si emulsions except for ulprospector. -
Better to take a pure anionic emulsifier and not glyceryl stearate SE which contains only about 1/10 anionics.Assuming it really were charge related and by extrapolating from the 10% pigment which work fine: either up magnesium stearate to about 1% or add roughly 0,5% anionics because you might require more than just the 0,2% I mentioned above. On the other hand, a “permanent” anionic emulsifier (magnesium stearate is pH dependent and hence not always 100% anionic) such as a sulphate might actually work with less…BTW did I already ask: What’s the pH before and after you add the custom blend?If high speed increases viscosity it usually means that it’s a “real” water in silicone emulsion (high shear/speed = small droplet size). As a rule of thumbs, lamellar emulsions can be made with a lower shear force.
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Pharma said:If high speed increases viscosity it usually means that it’s a “real” water in silicone emulsion (high shear/speed = small droplet size). As a rule of thumbs, lamellar emulsions can be made with a lower shear force.
Thank you! It’s very good to know this.
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Hello All!
An update for those who are also struggling with a foundation. As I suspected, it’s all about pigments. I found ready foundation blend consisting of: Titanium Dioxide (CI 77891), Hydorgenated Polydecene, Iron Oxides (CI 77492), Polyhydrixystearic Acid, Iron Oxides (CI 77491), Disteardimonium Hectorite, Iron Oxides (CI 77499), Propylene Carbonate (for those who are ingterested: https://www.glamourcosmetics.it/it/gc-base-bb-cream-warm-beige)
I got two colors (light and dark) and mixed to achieve desired shade. The downside is that you can’t play with shades. Bases are neutral and you can’t make them more pinkish or more yellowish. However, all my problems are resolved. I made two foundations with different emulsifiers and slightly different silicones/emollients and added pigments blend into a formed emulsion after cool down. Both have been stable for two weeks. I understand it’s not a “stability” test but provided that before they were separating right away it’s a success. These pigments do not break emulsions and I actually needed less to achieve medium coverage.
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Version with Cithrol DPHS:
Aqua 47.80% Betaine 3.00% Magnesium
Sulfate1.00% Sodium lactate 2.00% Euxyl PE 9010 1.00% PG 3.00% Dimethicone 5 10.00% Caprylic/Capric triglycerides 13.00% Magnesium Stearate 0.50% PEG-30 Dipolyhydroxystearate
(Croda’s)2.00% Cetyl PEG / PPG-10/1
Dimethicone (Abil EM 90)0.70% Polyglyceryl-3 Triolivate 0.50% Hydrogenated Castor Oil 0.50% Pigments blend 15% Lighter feel. Spiky and bouncy emulsion that is melting and super spreadable on skin.
The HCO above is not PEG-40 HCO it’s castor wax.
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Version with Dowsil 5225 Formulation Aid Aqua
61.00% Betaine 3.00% Magnesium
Sulfate1.00% Sodium lactate 2.00% Euxyl PE 9010 1.00% PG 3.00% Phenyl trimethicone 3.00% Caprylic/Capric triglycerides 1.00% Magnesium Stearate 0.50% Cyclopentasiloxane (and)
PEG/PPG-18/18 Dimethicone (Dow)8.00% Cetyl PEG / PPG-10/1
Dimethicone (Abil EM 90)0.70% Polyglyceryl-3 Triolivate 0.50% Hydrogenated Castor Oil 0.30% Pigments blend 15.00% Very viscous easier applied with a sponge (not a brush). It is so thick that could work for cushion packaging with a net (such as https://www.chanel.com/en_GB/fragrance-beauty/makeup/p/complexion/healthy-glow-makeup/les-beiges-healthy-glow-gel-touch-foundation-spf-25-pa-p184610.html#skuid-0184610)
I understand it’s a bit early to talk about shelf stability, but the fact they both withstood 38C in London last week is very promising.
The main difficulty of making a foundation is not making w/si emulsion. It takes some trial and error but doable. The main difficulty is to source good pigments. They must be coated and pre-disperced. Neither mineral makeup pigments, nor uncoated oxides, TiO2 pre-disperced in oil would work. Methicone coated TiO2 kinda works but still, when it’s not pre-disperced it makes a thin and poor quality foundation. I tried it all and I hope my experience is useful.
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Good to hear that you found a solution for your problem!
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Thank you @Pharma!
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@ngarayeva001
Well done! I hope you can achieve exactly the right hue for your skin!
It’s a pain to find the exact right colour, regardless of the brand. It’s almost always too dark for me, or even too light so I look either ill or like Morticia from the Addam’s Family (if I wore a black wig too). Or it has too much of a yellow undertone so I look like an alcoholic with liver cirrhosis. :confused:
And I’m done with buying several hues and mix them. What a hassle.I’ve recently bought Lancôme Teint Idole Ultra Wear (Beige Porcelaine) and this is one of the best so far.
(And I won’t even try something like La Prairie as I’m not willing to spend more than 200 euros per 30 ml :dizzy: )
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