Making Creams Part 2

In the previous article we looked at making a very simple cream following the 80:15:5 ratio for Water:Oil:Emulsifier. The formulation was just about as simple as it gets and here we're going to look at how we can tweak the basic recipe to improve the feel and stability of the cream

Emulsifiers will provide body to the cream but using emulsifiers on their own to thicken the cream is not ideal. There are a variety of materials available to the home formulator that can increase the viscosity of a simple emulsion.

Water Phase Thickeners

Are naturally derived polymers that work by absorbing water to swell up and increase viscosity. Cellulose derivatives like Hydroxyethylcellulose are frequently used in a variety of skincare products. Guar gum is another example of a naturally derived thickener. Others include Locust Bean Gum, and Xanthan Gum. There are many more but they may be difficult to source.

They are supplied as powders and are added to the water phase.

There will be many articles available explaining the best methods for incorporating these powders into the water phase – from first mixing the powder with a little glycerine, sprinkling onto cold water and allowing the polymers to swell before them using a high speed mixer to blend. Personally I simply sprinkle the powder into the heated water phase under the action of a high speed stick blender.

Water thickeners do not just build viscosity in the cream they also help stabilise the emulsion.

Xanthan – Readily available and easy to use. Usage rate is typically 0.5% to 1% though more can be used if desired. However above 1% Xanthan Gum can make your cream a bit stringy

Hydroxyethyl Cellulose (HEC) - not as commonly used as Xanthan but ought to be fairly easily available online. Usage rate is typically 0.5% to 1%. I prefer HEC to Xanthan as I find that creams using HEC as the water thickener have a nicer skin feel. HEC will also make crystal clear serums – if used at 1%. HEC will also tolerate alcohol very well and so can be used to make your own sterilsiing gel.

Guar Gum – is a highly effective water phase thickener that works well in creams. Use at 0.3% to 0.5%.

Ecogel - Lysolecithin (and) Sclerotium gum (and) Xanthan gum (and) Pullulan

is a relatively new addition to the range of water thickeners. It is in fact a blend of 4 thickeners which work synergistically to create a sophisticated multi-function agent. Not only will Ecogel act as a water thickener and emulsion stabiliser, it is capable of acting as an emulsifier. It is possible to create gel creams with a light and sophisticated skin feel. As a water thickener Ecogel can be used at between 0.3% and 1% and is compatible with a wide range of emulsifiers.

For more information click here:

Lecigel

is a gelling agent with emulsifying properties. It allows the increase in the viscosity and the stability of formulas. Suitable for both cold and hot processes, it also helps to adjust the viscosity at the end of the formulation process. Easy-to-use, it is compatible with most emulsifiers and is stable over a wide range of pH

For more information click here:

Oil Phase Thickeners

Tend to be selected from three groups of chemicals – Fatty Acids, Fatty Alcohols, and Butters.

(Note these 'acids' and 'alcohols' are not the same as we generally understand acid and alcohols).

There are a wide range of fatty acids and alcohols available for use in skincare but for the home formulator the following are usually easily available.

Stearic Acid (Fatty Acid) - can be derived from a variety of sources notably from natural butters such as shea and cocoa. Stearic Acid builds viscosity in a cream and also improves it's stability

Add to the heated oil phase at 1% to 2%.

Cetyl Alcohol (Fatty Alcohol) - Used as an emollient, thickener, or co-emulsifier in creams and lotions. It imparts texture and viscosity to creams and lotions. It is also used as an opacifier in shampoos. Please note that Cetyl Alcohol is not suitable for use as a stand alone emulsifier. It's role is to stabilise or thicken emulsions where a primary emulisifier (Emulsifying Wax blends, Olivem 1000 etc) is used.

Add to the Heated Oil Phase at 1% to 2% (3% can be used but tends to degrade the sensory feel of creams)

Cetyl Esters

Cetyl Esters is a blend of fatty alcohols and fatty acids that offer an easy way to increase the viscosity (thickness) of your creams and lotions while also improving the feel. The blend may include cetyl stearate, cetyl myristate, cetyl palmitate, myristyl myristate, and myristyl stearate. They are derived from vegetables,

Cetyl esters can be used anywhere you might use cetyl alcohol, although they will offer different qualities from the fatty alcohol. Using cetyl esters in a lotion or cream in the place of cetyl alcohol will give you a silkier feeling and a slightly thinner product. It will also lend stability to the emulsion.

Add to the heated oil phase at 1% to 2%.

Butters – because butters contain a high amount of stearic acid (and other fatty acids) for a more natural ingredients listing you can use plant derived butters (shea, cocoa, almond, etc) in the heated oil phase to add body to your cream. Using butters will give a more luxurious and richer feel to your cream. Bear in mind that butters should form part of the calculation for the oil phase. So if you are using 15% oil content and want to include say 2% Shea Butter reduce the liquid oils by the same amount. Limit the amount of butter to 3% as levels above 3% can make the cream feel grainy.

So let's trying modifying our basic formulation

Our original recipe was as follows

Water Phase
Water	80.00%	800g
Oil Phase
Sweet Almond Oil	10.00%	100g
Hazelnut Oil	5.00%	50g
Emulsifying Wax	5.00%	50g
	100.00%	1000g

We're going to use Xanthan at 0.5% as a water phase thickener and cetyl alcohol at 1% as an oil phase thickener. As we had used Emulsifying Wax at 5% to acts as the emulsifier and to provide body to the cream we are going to reduce it by 1% as the cetyl alchol will contribute thickness to the cream

Our new formulation is as follows

Water Phase
Water	79.50%	795g
Xanthan	0.50%	5g
Oil Phase
Sweet Almond Oil	10.00%	100g
Hazelnut Oil	5.00%	50g
Emulsifying Wax	4.00%	40g
Cetyl Alcohol	1.00%	10g
	100.00%	1000g

If we wanted to use butters in our formulation we would reduce the amount if oil by a proportionate amount and we could reduce the amount of cetyl alcohol a little to offset the extra body provided by the butter. Of course if we wanted a richer, thicker cream we could keep the cetyl alcohol at the same amount.

Water Phase
Water	79.70%	797g
Xanthan	0.50%	5g
	80.20%	802g
Oil Phase
Sweet Almond Oil	9.00%	9.00g
Hazelnut Oil	4.00%	40g
Shea Butter	2.00%	20g
Emulsifying Wax	4.00%	40g
Cetyl Alcohol	0.8%%	8g
	19.20%	192g
	100.00%	1000g

The best thing to do is to experiment. Try making small adjustments to the levels of oils, emulsifiers, and thickeners to obtain the viscosity and thickness you want.

Next article. Enhancing the cream – additional water phase and oil phase ingredients