Thursday, February 17, 2011

Learning to formulate: Modifying 60% water recipes

Unfortunately, I'm in a rush this morning with two craft groups to prepare for today, so analyzing how to make yesterday's cream drier will have to wait until the weekend! 

Not all lotions with 60% water will end up as a body butter or foot cream. I make what I consider a very nice hand lotion with 5% butters that is quite thick and occlusive, but not too greasy. So how can we modify the 60% water type recipe to be a lotion instead of a thicker cream?

If I go back to my basic body butter recipe, it looks like this...(I've modified the emulsifier to match the 25% rule...)

59% water
2% sodium lactate or glycerin

10% oils (4% light, 4% medium, 2% heavy, or just 10% of the oil of your choice)
15% shea butter (or butter of choice)
7% emulsifier*
3% cetyl alcohol

0.5 to 1% preservative
1% fragrance or essential oil blend

And I know this will be far too thick for my hands (although having said that, I've been using a shea body butter as a hand lotion for the last few weeks as I'm experiencing a lot of dryness and itching lately, but only at night when I know I won't be picking anything up or touching my iPod!), so I need to make some modifications. I'm happy with the cetyl alcohol in there, but I want to change the oils and butter amount.

If I think about my goal - I want an occlusive hand lotion that isn't too greasy but stays on well - I know I have to choose my oils wisely. I personally like a slightly greasier product, so I'll go with my favourite combination - fractionated coconut and either rice bran or olive oil. These offer a nice range of skin feel, polyphenols, phytosterols, and fatty acids for my trashed hands! Fractionated coconut oil sinks in quickly and feels more like an ester than an oil, that is to say it feels light and non-greasy. I think I'll go with rice bran oil as it contains a ton of nice fatty acids and phytosterols to help with itching and dryness.

But I need to switch the amounts around. If I go with 15% butters, I'm going to have a body butter instead of a hand lotion, so I'm going with 5% butters and 20% oils in this mix. I think I'll throw a little IPM in there for good measure (at 2%).

I could go with any butter here - shea butter might feel too greasy for some people, but I quite like it. You could use mango butter (less greasy), cocoa butter (occlusive), and so on. I'm going to use shea butter because I like what it brings to the skin feel and the benefits to my skin.

For the emulsifier, you can choose any you like. I'm going with Polawax as I find BTMS-50 feels too dry on my hands. But use BTMS-50 if you want a drier product.

I think I'm going to include 2% beeswax in this product as I find this makes it more resistant to washing off, so I have to compensate in my oil phase for that. I think I'll take out 2% rice bran oil in favour of the beeswax.

So here's the new oil phase...

16% oils (10% fractionated coconut oil, 6% rice bran oil)
5% butter (I'm going with shea butter)
2% beeswax
7% emulsifier
3% cetyl alcohol
2% IPM

For my water phase, I want to include some allantoin at 0.5% to act as a barrier ingredient (remove 0.5% from the water amount). I like to include aloe vera as well (so remove 10% from the water amount - total 10.5% so far), and I think I'd like to include lavender or chamomile hydrosol for the soothing properties (remove 10%, for a total of 20.5%). I'm going to throw in a little hydrolyzed oat protein at 2% as well for the film forming properties (remove 2% for a total of 22.5%). I already have 2% humectant there - should I increase it? I'll go with the sodium lactate and add a little more in the cool down phase. 

For the cool down phase, I always include cyclomethicone and dimethicone at 2% each in hand lotions for the increased slip and glide and slightly powdery feeling and for the barrier protection. So I need to remove 4% from the water amount and increase my emulsifier by 1% (remove 5% from the water amount, not up to 27.5% removed). I like to include honeyquat in my hand lotions because I like the extra humectant and the skin conditioning properties. I'll add it at 3% in the cool down phase (so remove 3% from the water amount, for a total of 30.5% of the water amount removed). And I'll include panthenol as a film forming humectant that can heal wounds (not a claim, but a hope!). So I need to remove 32.5% water from the water amount in this recipe. 

So let's take a look at the changes. 

26.5% water
10% aloe vera
10% lavender or chamomile hydrosol
2% sodium lactate or glycerin
0.5% allantoin
2% hydrolyzed protein

16% oils (10% fractionated coconut oil, 6% rice bran oil)
5% butter (I'm going with shea butter)
2% beeswax
8% emulsifier
3% cetyl alcohol
2% IPM

2% dimethicone
2% cyclomethicone
2% panthenol
3% honeyquat
0.5 to 1% preservative
1% fragrance or essential oil blend

Ta da! There's your hand lotion recipe. You'll notice we've reduced the water amount a bit, but we make up for it in the cool down phase with another 5% water soluble ingredients (panthenol and honeyquat), which still keep this as an oil-in-water lotion. 

If you find this lotion too thick, then you can start with the 70% water recipe and go through the same process to create a lighter feeling lotion. You want to tweak the oils and butters, add water soluble ingredients, and so on. You can increase or decrease the greasiness of the product by modifying your oils and butters, including or leaving out IPM and cyclomethicone, and altering your emulsifier. 

Join me tomorrow for more fun learning how to formulate! 


Frank and Nancy said...

Ready for the dumbest question ever? Does beeswax make a lotion feel waxy?

Also, please remember we were going to play with facial wipes. I'm really excited about that!

Frank and Nancy

Susan Barclay-Nichols said...

Hi Frank & Nancy. Not a dumb question! Yes, it will make it feel slightly more waxy, but it depends upon how much you use. I like to use about 2% in a lotion to make the lotion stay on a little longer, and I find this doesn't increase the waxiness too much.

I am going to be looking at facial wipes when I can get into the workshop again. It's -2˚C today, which is far too cold for anything other than shivering back there! The weather was warming up - we were up to 7˚C earlier this week, but I was feeling too horrible to play! - so I'm hoping I can get in there next weekend!

Stacy said...

Hi Susan,

Like many converts before, please let me thank you for this awesome resource. I am not a chemistry nerd (I am completely a nerd, I just played with computers rather than chemicals growing up), but with your help I'm learning...albeit slowly.

I’ve been hanging out here for a while now and I’ve done a lot of reading, but I would love to get a little guidance in my current formulation. I’ve done quite a few versions of this with different oils and amounts, but I’m still not happy with my final product. I started off with a recipe I found (I think here but I honestly can’t remember anymore) and have been tweaking away.

At this point I’m stripping it right down to the basics just to be able to pinpoint what my changes do. Here is what I used for my last formula:

78.5% Water
5% Almond Oil
4% Shea
3% Avacado
2.5% Stearic Acid
.5% Cetyl Alcohol
3.5% Polawax
1% Optiphen Plus
2% Sodium Lactate

The lotion turns out wonderfully and feels good (glide, absorption, etc) but the ‘moisturized’ feeling left on my hands is lacking. Is this something I can get out of oils alone, or should I be testing things like Dimethicone and Proteins? I’ll be adding Panthenol, but I’m not sure that will affect the feel of the lotion.

As an aside I went with the Stearic/Cetyl mix because I found that while 3% Cetyl absorbed really well, it left a dry powdery kind of feeling I did not like.

Thanks for any advice you can give!