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 firstname.lastname@example.org).
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).
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
- 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.