I spent the last weeks experimenting with emulsions and emulsifiers, because my skin kind of changed its preferences and needs lately.
Methylglucose sesquistearate-based emulsions started to feel too waxy for me and I was looking for something moisturizing and light at the same time. I enjoy using hydrogels and especially my last version of the gel toner, but I also like emulsions and fluids, so… I decided to try with lecithin-based emulsions.
Lecithin is actually a group of substances that we can find naturally in egg yolk, soybeans, rapeseed oil or sunflower oil. These molecules are amphiphilic: they have a hydrophilic portion and a hydrophobic tail. Which means… they are surfactants! That’s why long hair enthusiasts sometimes use egg yolk to wash their hair: it works perfectly, because lecithin is a surfactant and can cleanse your hair and remove excess sebum.
Lecithin mainly consists of glycerophospholipids, among which the best known is phosphatidylcholine (PC). PC can form liposomes, bilayer sheets, micelles and lamellar structures in aqueous solutions. Like all the other surfactants, it can keep oil phases and water phases together, acting as an emulsifier.
You can find lecithin and its derivatives in various forms. For example, you can find raw lecithin even at the supermarket or pharmacy, as it is used as food supplement. It is sold in big jars as granulate and doesn’t cost much. I paid my 500 g jar something like 8 €.
But you can also find lecithin derivatives specifically meant for cosmetic formulation in the supplier shops, for example lysolecithin and hydrogenated lecithin (Phospholipon 80H). Germans looooove Phospholipon 80H, therefore you can find it easily in all German supplier shops.
What is the difference between Phospholipon 80H and raw lecithin? Basically, the amount of PC in Phospholipon 80H is much higher than in raw lecithin, therefore a lower percentage is needed in the formulation to act as emulsifier. It’s a sort of purified version of raw lecithin and a part from working flawlessly at low dose, it does not have the strong scent of raw lecithin and the emulsions are stable also in presence of many hydrating substances (while raw lecithin tends to make pudding-like emulsions when you start to add up chemicals).
After weeks of experiments, I can suggest you to use them like this:
Raw lecithin (use level 6-12%): use it in simple fluids and cleansers in which you don’t add too many hydrating functional ingredients in the cool down phase.
Phospholipon 80H (use level 0,5-3% together with sucrose stearate 0,5-1%): use it in creams and fluids where you want to play more with functional ingredients.
Base formulas with raw lecithin
General guidelines:
Lecithin granules are inserted in the water phase. I suggest to add the ingredients in the following order: glycerin, xanthan gum (mix to disperse xanthan gum in glycerin), lecithin granules, and finally water.
Put the water phase in the water bath while you prepare the oil phase.
Once water phase and oil phase are both hot (and oil phase is melted), quickly stir the water phase with the immersion handblender in order to break completely the lecithin granules.
To make the emulsion, add the water phase to the oil phase while stirring, then start mixing with the handblender. From here on, you can proceed in the same way as in the cream basic procedure.
Fluid with 4% fat
A: Water phase
%
Water
82,6
Glycerin
4
Xanthan gum
0,4
Lecithin granules
6
B: Oil phase
%
Consistency factors
1,5
Butters
1
Liquid emollients
3
C: cool down phase
%
Benzyl alcohol/dehydroacetic acid
0,5
Potassium sorbate 20% solution
1
Fluid with 15% fat
A: Water phase
%
Water
69,6
Glycerin
4
Xanthan gum
0,4
Lecithin granules
8
B: Oil phase
%
Consistency factors
1,5
Butters
1
Liquid emollients
14
C: cool down phase
%
Benzyl alcohol/dehydroacetic acid
0,5
Potassium sorbate 20% solution
1
Cream with 15% fat
A: Water phase
%
Water
66,1
Glycerin
4
Xanthan gum
0,4
Lecithin granules
10
B: Oil phase
%
Consistency factors
3
Butters
2
Liquid emollients
13
C: cool down phase
%
Benzyl alcohol/dehydroacetic acid
0,5
Potassium sorbate 20% solution
1
Cream with 28% fat
A: Water phase
%
Water
51,1
Glycerin
4
Xanthan gum
0,4
Lecithin granules
12
B: Oil phase
%
Consistency factors
3
Butters
2
Liquid emollients
26
C: cool down phase
%
Benzyl alcohol/dehydroacetic acid
0,5
Potassium sorbate 20% solution
1
Cleanser fluid with 5% fat and 6,6 active surfactant matter
If you have read the Nanotechnology in cosmetics series you should know that I believe liposomes are useless in DIY cosmetics for several reasons. However, here they are useful from the formulation point of view. As I said before, with granular lecithin you cannot afford to play much with functional ingredients because the texture of the emulsion can easily become pudding-like and not very smooth. Among the functional ingredients that do this trick there is sodium hyaluronate/hyaluronic acid. With liposomes, that are made of PC therefore are very with lecithin, this does not happen. What you add to the formula is basically a mixture of PC (=more lecithin) and a little bit of hyaluronic acid that will not disturb much the emulsion.
Lecithin face cleanser (5% fat, 6,6% active surfactant matter)
A: Water phase
%
Water
58,1
Glycerin
7
Xanthan gum
0,4
Lecithin granules
6
B: Oil phase
%
Sucrose cocoate
4
Coco glucoside
8
Rapeseed oil
5
Salix Nigra (Willow) Bark Extract (10% salicylic acid)*
10
Benzyl alcohol/dehydroacetic acid
0,5
Potassium sorbate 20% solution
1
*This is not pure salicylic acid. I used the functional ingredient sold by Aroma-zone as “vegetable salicylic acid” but keep in mind that it is actually a Salix nigra extract that contains 10% of salicylic acid.
This preparation does not need to be heated up. Prepare the water phase and let it rest at room temperature for a while, to allow lecithin granules to hydrate and swell. Mix quickly with the handblender to break the granules, then add the rest of the ingredients and mix again.
With Phospholipon 80H
Face cream (15% fat)
A: Water phase
%
Water
64,6
Glycerin
4
Xanthan gum
0,4
B: Oil phase
%
Phospholipon 80H
3
Sucrose stearate
1
Cetyl alcohol
1
Cetyl palmitate
2
Shea butter
2
Tocopheryl acetate
1
Grape seed oil
3,5
Squalane
1
Argan oil
3,5
Olive oil
2
D: cool down phase hydrophobic
%
Hemp oil
2
E: cool down phase hydrophilic
%
Sodium lactate 60% solution
5
Urea
2
Sodium lactate/lactic acid buffer pH 4 (0,2 M, 0,1 M)
Gothic's Hollow 