Friday, February 18, 2011

Learning to formulate: Butters, oils, and thickening

As we've been working with the 70% water recipe and the 60% water recipe, you can see the main difference between the two tends to be the amount of butters to oils. In the 70% recipe, we use more oils than butters; in the 60% recipe, we tend to use more butters than oil (not in the cream recipe, but we do in the body butter recipe). Butters contain stearic acid, which will thicken our products quite well, and this is one of the main reasons the 60% water creams are thicker than the 70% water lotions. (The other reasons are a lower water phase and an increase in our emulsifier, which is also a great thickener.)

If we made a 60% water recipe without butters, what would happen? We'd get something on par with a lotion, thinner, less occlusive, and more glidy (if you're using cetyl alcohol). If we chose our oils wisely and went with light feeling oils or esters, a 60% water lotion can feel as thin as an 80% lotion, especially if we leave out the thickeners.

Here's a 62% water lotion - the shea, soybean, and sesame oil 6 ingredient lotion - without thickeners and butters. Although I used 10% shea butter, it's still an easily pumpable lotion of about medium thickness. If I'd included 3% stearic in this recipe, it would have been quite thick. If I'd included 3% cetyl alcohol, cetyl esters, or cetearyl alcohol in this recipe, it would have been thicker with some glide. If I'd used something like mango or cocoa butter, it would also be much thicker than using refined shea butter. By leaving out the thickening agents - our heavier butters, fatty alcohol, and fatty acids - I made a lotion instead of a cream.

And consider this lotion with a 62% water phase - hand lotion with cetearyl ethylhexanoate and cocoa butter - which is very light and creamy feeling. This time I included cetyl alcohol in the mix as well as 6% cocoa butter, but it ends up being a medium weight hand lotion that feels really lovely and isn't too greasy. By using an ester like cetearyl ethylhexanoate, I've compensated for the greasy feeling of the cocoa butter but kept the barrier protection it offers. If we used a thicker oil, like avocado or jojoba, increased the cocoa butter to 10%, and used stearic acid instead of cetyl alcohol, you'd see a very different product.

So there's something to think about. Let's say you've made an awesome hand lotion and want to make it slightly thicker without changing the ingredients, then increase the butter amount or change your fatty alcohol or acid. If you've made an awesome body butter and want to use it as a hand lotion, decrease the butters and increase the oils to get a thinner product.

Join me tomorrow for more fun formulating with thickeners!


Will said...

A weird question for a Friday!

I read in a press release where Dial Corp is attributing significant skin benefits in their new products to Vitamin F, aka Omega-2, aka cod liver oil (one of many).

Have you ever experimented with cod liver oil in a lotion?

I'm curious as heck, but I can't remember if it had a smell.

What's your take on that? Seems Great-Grandma with her cod liver oil was ahead of her time ;D

Thanks, Will

Will said...

OOPS, make that Omega-3.

Rocio said...




Susan Barclay-Nichols said...

Hi Will! Not a weird question - in fact, I wrote this post to address it!

Susan Barclay-Nichols said...

Hi Rocio. You don't need to shout! The whole point of this formulating series is to give you the tools to create your own lotions. And there are debates about what kinds of ingredients will actually provide what we think of as anti-aging benefits.

The first place to look is in the emollients section of the blog. Here I have included everything I know about oils, butters, and exotic oils. Look for the properties you want in your product in those oils. Next, check the extracts section, if you're interested in learning more about botanical ingredients. You might want to read the sections in the skin chemistry and types section to see what each skin type needs (for instance, do you include more humectants or film formers?). Then figure out which cosmeceutical ingredients will work for you and read up on those. (I don't know much about cosmeceuticals because I don't use them in my products - they're simply out of my price range, for the most part). The first step is figuring out what base you'd like to use for the product, then adding all the goodies.

Hope this helps!

Rocio said...

Dear Susan:

My best regards