Learning to formulate: Small changes make big differences in the oil phase

Yesterday, we took a look at making some small changes to the water phase to create a more humectant-y product. Today, let's take a a look at making small changes to the oil phase! Keep in mind that if you change the oil phase by increasing the oil amount, you need to modify the emulsifier and modify the water amount. For more information on this, please click here or click here. For now, let's take a look at modifying the oil phase without increasing it.

Some small changes I like to make in my oil phase include adding some IPM or IPP - usually at 2% - to decrease the feeling of greasiness. I like to include cyclomethicone at 2% and dimethicone at 2% in the cool down phase. Cyclomethicone will increase the slip, glide, and skin feel of the product, making it feel more powdery. Dimethicone will increase slip and glide and behaves as a barrier ingredient. Adding 1% Vitamin E will help retard rancidity in my oils (although they are longer shelf life oils). And I don't have a thickener in here! I think including 3% cetyl alcohol will make this lotion much thicker, a more body butter-y type consistency with all that shea butter, so I'll include that as well.

These small changes add up quick! I need to increase my oil phase by 10% here, which is quite a bit. So I think I'll do it by removing some of the oils in the product so I don't have to mess with increasing the emulsifier and decreasing the water amount. I think I'll reduce the shea butter to 5% as I would like a product that that can go into a pump bottle, and 10% shea butter plus 3% thickener tends to equal more of a body butter consistency. So where do I find the other 5%? I think I'll reduce the oils to 7.5% each. This will make every still equal 30% (7.5% soybean oil, 7.5% sesame oil, 5% shea butter, 3% cetyl alcohol, 2% IPM, 2% cyclomethicone, 2% dimethicone, 1% Vitamin E for a total of 30%.)

As with yesterday's small changes, here's the recipe we'll be using - the six ingredient soybean, sesame seed, and shea butter lotion (click for the original version).


NOT SO MUCH A SIX INGREDIENT LOTION ANY MOREWITH SHEA, SOY BEAN, AND SESAME OIL (modified to include some small oil phase changes)
HEATED WATER PHASE
32% water
20% aloe vera
3% glycerin
0.5% allantoin
2% hydrolyzed oat protein
2.5% sodium PCA

HEATED OIL PHASE
5% refined shea butter
7.5% soy bean oil
7.5% sesame oil
2% IPM or IPP
3% cetyl alcohol
6% BTMS-50

COOL DOWN PHASE
2% cyclomethicone
2% dimethicone
1% Vitamin E
2% panthenol
0.5% powdered chamomile extract
0.5% liquid Germall Plus
1% fragrance oil (Clementine Cupcake)

If you didn't want to alter the butter and oil amounts - you want to keep them at 10% shea butter, 10% soy bean oil, and 10% sesame seed oil - you'd have an oil phase of 40% (30% original oils and butters with 10% more added). This means you'd need to increase your emulsifier - if we're using Polawax as an example, you'd add 2.5% more emulsifier - and decrease the water amount by 12.5% (10% more oils, 2.5% more emulsifier). With BTMS-50, we're not as picky about increasing or decreasing the emulsifier because we don't need to follow the 25% rule, but I'd increase it to 8.5% anyway. With other emulsifiers, you'll have to consult your notes or your supplier.

So what will these small changes do to the skin feel of the lotion? My original creation was a medium weight lotion with about a medium greasiness level. Decreasing the shea butter and adding the IPM will result in a less greasy lotion. Adding the cyclomethicone will also have this effect. Adding the dimethicone will increase the greasiness a bit (and the shine!) but adds a much needed barrier ingredient (as will the allantoin from yesterday's recipe), which is a good thing during the winter months! Adding the cetyl alcohol will increase the slip and glide, as well as the thickness of the lotion. Despite reducing the shea butter, we should see the same or slightly thicker consistency thanks to the cetyl alcohol.

Join me tomorrow for some more ideas on small changes...