Emulsifiers – what should I buy and how much to add?

Which emulsifier to buy and how much to add

With so many unstable recipes available, it’s no wonder many lotions fail to emulsify or stay emulsified.

Important: Beeswax and cetyl alcohol are NOT emulsifiers.

Emulsifiers vary greatly – some work really well and some are less effective.  Check the supplier’s website for the inci name of the ingredients which make up the emulsifier.    For an emulsifier described as “self emulsifying” to have a chance at performing as such, it should consist of at least two separate emulsifiers.

Which emulsifier should a newbie buy?  The following are reliable blends and make for a good starting point: Polawax NF or a blend of cetearyl alcohol plus polysorbate 60 or, for a natural emulsifier, Natragem EW is sold by Penny Lane Organics in Canada and in Europe it’s sold as “Ecomuls” (not to be confused with Ecomulse) by behawe.com, hobby-kosmetik.de or rosarome.de. If you have oily skin, lotionpro or lexemul is a good choice. There are lots of other emulsifiers available, for example, liquid crystal emulsifiers, such as olivem and cetearyl glucoside have their own quirks so maybe a bit tricky for a newbie.  If you are intending to use emulsifiers not listed here do conduct a search of the inci name to see the original supplier’s data sheet so you can get to know it’s processing requirements and suitability.

How much to use?

For Polawax NF and cetearyl alcohol + polysorbate 60 and Natragem EW, a starting guide is to add it at 25% (one quarter) of the total of the oil soluble ingredients in your recipe.  (Note: Oil soluble ingredients can also be found in your cool down phase, for example, fragrance, vitamin E, cyclomethicone). So if your oil soluble ingredients excluding the emulsifier totals 10% then you’ll be using 2.5% emulsifier. Lotionpro/lexemul is more effective at low levels than polawax so can be added at only 15% of the total oil soluble ingredients instead of 25% but do not add it below 3% in your recipe.  It is quite a “thin” emulsifier so you’ll need to add an extra 2% cetyl alcohol.  For other emulsifiers, do check the supplier’s data sheet for information on how much to add.  If you cannot find this information, start with this 25% guide rule.

If your lotion contains a high oil phase (eg over 27%), I find this 25% rule often isn’t a linear relationship.  In these circumstances, it’s best to only use enough emulsifier to do the job – too much could end up causing your lotion to be draggy/soapy.

Once you’ve a few lotions under your belt you might wish to try other emulsifiers, and even create your own blend.  Here’s a calculator which will walk you through the HLB system.

Don’t forget to add a stabiliser to your lotion and use a stick blender rather than a coffee frother/whisk, otherwise your lotion may not stay emulsified!!

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Useful links:-

Lotion / Moisturiser tutorial

Another no heat, quick lotion/moisturiser using cold process technology

Cold process emulsifiers are becoming popular as manufacturers search for ways of reducing costs and greener production methods.  The conventional way of forming a emulsion is to heat the two phases separately then bring them together with mixing.  It takes a lot of time and energy to heat the ingredients to 70°C and hold them there for 20 minutes.

Following my previous post on the cold emulsifier, Sucragel –http://makingskincare.com/2013/11/20/quick-no-heat-lotion/ I decided, to try another cold emulsifier, Durosoft from Stephenson Personal Care which is a range of polyglycerol esters produced from vegetable oils and glycerin – http://www.stephensonpersonalcare.com/products/durosoft/.  The Durosoft range can serve as emulsifiers (o/w, w/o and co-emulsifiers) and solubilizer. They are both water and oil soluble and cold processable and PEG free.

The chemist at Stephenson, kindly sent me a sample of one of the range – Durosoft PK (INCI: Elaeis Guineensis (Palm Kernel) Oil Polyglycerol-4 Esters) and provided formulation tips.   (If you would like to try the emulsifier, the sales contact is james.clews@stephensongroup.co.uk).

The formula below produces a gel-type lotion / moisturiser (due to the sodium polyacrylate) which spreads well and sinks in easily.  I found Durosoft easy to work with, particularly compared to Sucragel.

I would not advise using silicone with Durosoft, however, it is fine with electrolytes.  The sodium polyacrylate I have included in the formula however, is sensitive to electrolytes so do not include ingredients such as protein, aloe vera, sodium lactate, green tea etc.

As we are not heating and holding our emulsion, don’t forget to pre-boil the water beforehand (to kill some of the non-endospore-forming bacteria), let it cool then use immediately.  The preservative should be used at the supplier’s recommended level (0.5% in the case of liquid germall plus) and, as always, do test preservative efficacy with new formulations.

FORMULA – use this recipe calculator to convert the % below into grams – http://makingskincare.com/recipe-calculator/

PHASE A– water soluble ingredients
76.7% deionized/distilled/purified water (pre-boiled and cooled).
3% glycerin
0.5% liquid germall plus (for alternative preservatives see – http://makingskincare.com/preservatives/)
1.5% Durosoft PK

PHASE B – oil soluble ingredients (the gum+sodium polyacrylate are water soluble but putting them here helps wetting and reduces clumping)
0.3% xanthan gum
15% vegetable oils
1.5% Durosoft PK
0.4% sodium polyacrylate (to thicken, stabilise)
0.1% vitamin E
1% fragrance/essential oil

polyglycerol-illustrator-1

polyglycerol-illustrator-2

  • Pre-boil the deionized/distilled/purified water and allow to cool (this is to kill some of the non-endospore-forming bacteria).
  • Put Phase A (water phase) contents into a container, mix until homogeneous.
  • Put Phase B ingredients into a separate container, mix and then add to the Phase A (water phase).
  • Stick blend until homogeneous.
  • Done!

No heat, quick Natural lotion / moisturiser

Mixing

Cold process emulsifiers are becoming increasingly popular as manufacturers search for ways of reducing costs and greener production methods.  The conventional way of forming a emulsion is to heat the two phases separately then bring them together with mixing.  It takes a lot of time and energy to heat the ingredients to 70°C and hold them there for 20 minutes.  For this reason cold process emulsifiers are becoming increasingly popular.  Unfortunately there are a limited number of suitable emulsifiers and those available are often restricted in application.

I’ve been experimenting with Sucragel which was made specifically made to produce a stable emulsion using cold processing (INCI: Glycerine & Prunus dulcis (Sweet Almond) oil & Sucrose Laurate & Citrus aurantium dulcis (Orange) Fruit Water).  You can buy it in the UK from Gracefruit and Ofasimplenature. In the US it’s sold by www.kinetiktech.com.  It comes in various forms. The CF version can be used for veggie oils, esters and silicones and the AOF version is strictly only for veggie oils. The AOF BIO version produces a slightly thicker lotion and contains 94% certified organic ingredients and is certified by the Soil Association and EcoCert so is considered “natural”.

I had a little chat with the cosmetic chemist at Alfa who created sucragel at SCS Formulate who provided some useful formulating tips.

Sucragel already contains lot of glycerin so there’s no need to add much to your recipe but sucragel has some downsides. It can’t create a thick lotion – doesn’t matter how many butters, cetyl etc you add it just will not thicken!   Sucragel’s creator informed me that if you add water then sucragel will take on the viscosity of the water .  So, we will have to rely on xanthan gum  for thickening, and quite a lot of it – 1% minimum.  So, in my opinion, it’s best to save sucragel for lotions for oily or normal or slightly dry skin and rely on your normal hot process lotion for formulas for dry skin or use one of the recipes in the lotion tutorial in this blog – http://makingskincare.com/how-to-make-a-lotioncream-part-1-equipment-and-ingredients/

Sucragel also doesn’t like electrolytes and cationic ingredients so to avoid lotion separation do hold off on adding ingredients like: sodium lactate, aloe vera, green tea, proteins and quats.  It also doesn’t like stearic acid.

It also needs to be made in a certain way/order and a stick blender used as a mixer so that it will emulsify properly.  Fussy eh?

Here’s a recipe for a very light lotion or face moisturiser for normal skin:-

WATER PHASE
86.9% distilled/deionised/purified water (do pre-boil the water (adding a bit extra as some will evaporate) in the microwave to kill some of the non-endospore-forming bacteria)
1% xanthan gum
1% glycerin
0.5% liquid germall plus (do not use optiphen as the lotion will separate. Please see here – http://makingskincare.com/preservatives/ for info on why we are adding a preservative and also for reviews of alternative preservatives)

OIL PHASE
3% sucragel CF or AOF
7% liquid vegetable oil (if you have the CF version you can include esters and silicones without risking lotion separation)
0.1% vitamin E (note: vitamin E is not a preservative)
0.5% fragrance/essential oil

(Note: deviations from this recipe and method/order of making it may result in lotion separation as sucragel is really fussy I’m afraid).

(For a more emollient lotion you can alter the above recipe to include 20% oil, 5% sucragel and delete the glycerin as Sucragel contains a lot of glycerin already and use 72% water.)

1. Boil your distilled/purified/deionized water in the microwave to kill some of the non-endospore-forming bacteria.  Do add some extra water before you boil it as some will evaporate.  Let the water cool to room temperature.  

2. Put all your water phase ingredients in one container (except the gum).  Then sprinkle the xanthan gum on the top, trying to make sure it doesn’t clump. Mix well.

3. In a separate container (your oil phase container), put your Sucragel, then add the rest of the oil phase ingredients to the Sucragel mixing with your stick blender as you add each ingredient.

4. Slowly pour the oil mixture into the water phase ingredient container (pour directly into the vortex) whilst mixing with the stick blender vigorously for 3 minutes. (Note: sucragel is fussy, so we can’t use a fork, whisk or other type of mixer).

More recipes – http://www.alfa-chemicals.co.uk/Libraries/Sucragel/Sucragel_Formulation_Booklet_2013_1.sflb.ashx