Wednesday, September 15, 2010

Deodorants: A recipe with alcohol and propylene glycol

As I mentioned yesterday, every clear gel deodorant stick starts off with sodium stearate and a polyol. Generally we'll use about 6% to 8% sodium stearate, a goodly portion of the polyol - one of the glycols or glycerin - and perhaps a little alcohol. Here's a basic recipe from which we can start, then we'll tweak it! (I found this recipe originally on a pharmacist's formulating site, hence the boring name!)

7% sodium stearate
65% alcohol
25% propylene glycol
3% cyclomethicone

1. Weigh/measure ingredients.
2. Melt sodium stearate
3. Mix in alcohol, propylene glycol, and cyclomethicone and add to the melted sodium stearate.
4. Mix well, cool slightly, and pour into stick molds.

As I also mentioned yesterday, sodium stearate has a melting point of about 245˚C, so we can't just melt the sodium stearate. You'll have to use the alcohol as the solvent for the sodium stearate. You can include the propylene glycol in that solvent, so we'll melt the first three ingredients together and add the cyclomethicone at the end with our fragrance oil and preservative. (The cyclomethicone is there to add slip and glide to the product.)

Doesn't this look boring? Just a clear stick with no nice things for your skin, no destinkifiers, no fragrances. So what can we add to the mix?

Our water soluble esters would offer some slip and glide with some emolliency. Something like PEG-7 olivate would offer some moisturizing, whereas Crodamol STS would offer some great emolliency, as well as detackifying and spreading properties. We can add either of these at around 3%, and you can use it in place of the cyclomethicone. I used Crodamol PMP at 3% in my version and it felt very nice, glidy and not sticky. (And at that level, I didn't notice the weird smell of the PMP.)

You could add some aloe vera or other botanical ingredients at 5% or so, and the addition of witch hazel would make it more astringent and more cooling on your skin (but we have alcohol in this recipe, so the cooling effect is kind of redundant). One down side of using alcohol is the possible sting factor after shaving - test this before making this your post-shaving deodorant!

What can we use as destinkifiers in this recipe? We can add a fragrance oil at 1% - I used Yuzu from Brambleberry, but you could use any fragrance or essential oil you like. Some people like tea tree oil as it is anti-bacterial or lavender as an antiseptic. Or we could use Tinosan, an anti-bacterial preservative that's being used in most of the anti-bacterial products like soaps and hand sanitizers. (More about this ingredient tomorrow.)

As an aside, if you want to use Tinosan, you can't use any cationic ingredients like cationic polymers in this product. If you don't want to use Tinosan, you apparently don't need to use a preservative because alcohol is self-preserving at over 60%. I'd still add one...

So let's take a look at our modified recipe!

7% sodium stearate
60.7% alcohol
25% propylene glycol
3% water soluble ester (Crodamol PMP) or cyclomethicone
1% fragrance oil
0.3% Tinosan

Weigh the sodium stearate, alcohol, and propylene glycol into a heat proof container, place in double boiler, and heat until the sodium stearate is melted. Remove from the heat and add the ester, fragrance oil, and Tinosan. Pour into deodorant tubes and let set. Rejoice!

Join me tomorrow to learn a little more about Tinosan!


Mountain Farms Soap said...

I am just wondering where you get your ingredients like Peg 7 etc. Thanks

Susan Barclay-Nichols said...

I bought my PEG-7 olivate from the Herbarie, and the rest of my esters from the Personal Formulator. I can't really get them in Canada, which is most unfortunate.

mali said...

Hello, Susan!
These recipes seem easy enough to try, but I don't have sodium stearate( I make CP soap, so I can use it instead? Or is it exactly stearate which makes us less sweat?

Susan Barclay-Nichols said...

Hi Mali. No. If you put CP soap under your arms all day you'd feel really sticky and slightly foamy, and you'd possibly irritate sensitive areas. You really do need sodium stearate to make these recipes work.

mali said...

Thank you for the answer!
Still I don't understand why we need exactly this sodium salt. I'm not strong in chemistry, to say the least :) Does stearate help to reduce sweat production, or maybe it kills bacteria?
I really want to try this cause I don't like the one with baking soda and coconut oil for its alcaline condition(and it doesn't work for me).

Susan Barclay-Nichols said...

Hi Mali. Have you read the initial post on deodorants?

The role of sodium stearate is to make the gel stick. Without it, we'd just have some liquids floating around in a container. We add the sodium stearate to thicken the liquids and turn them into a hard gel bar.

Anonymous said...

Hi Susan,
I was wondering where do you buy sodium stearate? can it be replaced with, say, some other thikner (like stearyl alcohol or so)?
thank you

Anonymous said...

sorry, addition to the above comment:
not stearyl alcohol but stearic acid

Robert Williams said...

Great blog post!

Terri said...

Susan: I made a 100-gram batch, using the amounts listed, but it didn't solidify, even after letting it sit overnight. I suspect one of two possible ingredients might be the culprit. First, I used rubbing alcohol from the drugstore for the alcohol. Can you let me know if I was supposed to use something else? Second, I ordered the sodium stearate from an supplier I never used before. It arrived as a white powder in a plain, zip-lock plastic bag. Another supplier said its sodium stearate was "flake-like granules." Any thoughts on whether the "sodium stearate" I received might not be the real deal?

I have made bunches of your recipes, and they all have worked in the past, so I don't suspect a recipe error.


Terri said...

One more possibility, in addition to the above, is that I may not have completely dissolved the sodium stearate. It look dissolved when I took it off of the heat, but since it was in powder and not granular form, it wasn't easy to tell.

Susan Barclay-Nichols said...

Hi Terri. Did you heat and hold it? I'm wondering if you can't reheat it and hold it for a period of time to make sure everything has melted well. My sodium stearate is in flakes, but it could come in other ways. (This is one reason I don't trust buying from anyone other than a never know. I had someone try to tell me zinc stearate and sodium stearate were the same thing. They are not!) I think the alcohol might be an issue as you might have isopropyl alcohol? I'm not really sure. Can you try to reheat it and hold for a while, then let it set? It should set when the product cools, which isn't more than an hour or so. Let me know what happens.

Terri said...

Susan: I made a second batch, and I made sure to heat and hold for 20 minutes. I also used a 99% isopropyl alcohol instead of the 70% isopropyl rubbing alcohol I originally used and I still had unsatisfactory results. Should I be using something other than isopropyl alcohol?


Susan Barclay-Nichols said...

Hi Terri. I've been using denatured alcohol from my local supplier, which is ethanol, and I've not had a problem. I'm not sure why isopropyl alcohol might not work, but it sounds like it might be worth giving the ethanol a try. Make sure that everything is really well melted - heat and hold it to make sure - before combining and pouring into the deodorant containers, too. (Not that you didn't do that, but it seems to be a reason the recipe fails....)

MargaRAT said...

Which gave you a better stick deodorant; the propylene glycol or the dipropylene glycol?
Sources for ingredients: I will be getting propylene glycol from Thrifty Foods (ask the pharmacist to order it for you). I got sodium stearate at Rexall Drugs. It was $70 for 454 grams!!! It is pharmaceutical grade, however. I guess that's why it was so $$$$$.

Anonymous said...

Hi, is it possible to replace alcohol with witch hazel?

SweetLily said...

Can I use aloe vera instead of alcohol? If so, will the dipropylene glycol be enough to still melt the sodium stearate? Thanks in advance!

Susan Barclay-Nichols said...

Hi Anonymous and Sweet Lily. You can't replace the alcohol with just anything; it has to be a polyol, something like glycerin (which would be far too sticky) or propylene glycol. Witch hazel and aloe vera don't contain the necessary bits to create a chemical reaction with the sodium stearate.

From this post: We need a polyol, which is an alcohol containing multiple hydroxyl groups. We can use glycerin or any of the glycols (propylene, di-propylene, hexylene, or butylene glycol) to create the clear stick with the sodium stearate. You can use alcohol as well, but you'll need to include one of these polyols with it. (The sticks with alcohol or witch hazel will offer a cooling effect, so there's a bonus to using those liquids.) Some deodorant sticks also contain water, generally to help melt the sodium stearate.

Please take a look at the other posts in this series, including this one with glycerinor this one with dipropylene glycol with a bit of witch hazel in it or the other ones with the label "deodorant".

Alaska Grisco said...

Hey Susan, I looked up Herbarie and was wondering if the AquaEm or Cromollient SCE would work in place of the water soluble esters? Thanks!

Susan Barclay-Nichols said...

HI Alaska. Please see today's Friday Wonderings to see the answer to your question!

Lila McGrew said...

Hi Susan,

I realize this is an old post, but I'm new to making my own products. Like Mali above, I make CP soap and am curious why my soap won't work in place of the pure sodium stearate.

My assumption has been that deodorant manufacturers use sodium stearate because it's a lot cheaper than other forms of soap made from more expensive fatty acids/oils.

BUT - if I need pure sodium stearate, I can easily make myself using the CP method with stearic acid - available through my soap supply store. Would it be possible to use just the stearic acid if it's sole purpose is as a thickener?

If I may, I would like to address one of Mali's questions. Deodorant doesn't stop sweating. Ingredients in deodorant inhibit the growth of bacteria - which are the cause of the odor.

From what I've heard, (and I could be totally off base here) an alkaline based product makes the area inhospitable to bacterial growth, thereby reducing odor. Soap is alkaline and I've used it as deodorant with excellent results, but like Susan said, it is irritating. Many use milk of magnesia as deodorant (ph 10) with good results. I have as well, but it doesn't last as long as I would like.

I had been contemplating a soap recipe that is low lather and adding m-o-m and a few other ingredients to soften it and increase slip, but seeing now that deodorant is only about 6% sodium stearate, I'm re-evaluating that idea.

Susan - you've obviously done a lot more research in this area than I have, so I'm really interested in your thoughts on what I've written. And - thank you for sharing all your knowledge with us - it is much appreciated.

lilamcgrew said...

Another Thought about CP soap for deodorant.

Thinking back on my early soap making, I once tried adding stearic acid to a soap recipe to harden it some. 5% created a bar so hard that no one liked it. It also traced incredibly fast - making it unworkable in very short order.

A stearic acid soap (sodium stearate) is going to be hard as a rock which is why (I'm thinking) only 6-8% will produce a solid deodorant when combined with all that liquid.

I've developed a recipe, based on all the info Susan so graciously provided and some of my past experiments, using a bar of my plain cp soap. I'll follow up with the recipe and the results in a few days.

Sânziene şi Mătrăgună said...

so, looks like I am not the only one with problems making a solid stick :)

I tried PG, DPG - nothing worked with 10% Na Stearate to get a solid stick. bummer :-(

Anonymous said...

5% of sodium stearate should be enough to get a solid stick. try to melt it together with water at 90 degree and stir longer to make sure it clear. if the base with higher % of propylene glycol, around 75 degree it can melted very quickly.

Sânziene şi Mătrăgună said...

I used 10% sodium sterate and almost 70 or 75% either dipropylene glycol or proylene glycol. no luck in making a solid stick. it was melted alright - I had a clear solution.

Susan Barclay-Nichols said...

Hi Sanziene. Two questions - are you heating it to the very high temperatures anonymous suggested? And what kind of sodium stearate are you using? I ask this question because I know some people are making their own according to a French blog, but there's no way of knowing if this is completely sodium stearate or something else. This is my go-to recipe, and I've never had problems with it, so I'm completely dumbfounded as to what to suggest!

Sânziene şi Mătrăgună said...

Hi Susan!

I am using Na Stearate which I buy from a supplier.

I heat the sodium stearate in either propylene glycol or dipropylene glycol until I have a clear solution; then , after it slowly cools down, I add the remaining ingredients.

1. I tested the same recipe with home made stearic acid soap (sodium stearate) and with store bought sodium stearate. same result
2. both recipes above contained 5% aluminium chlorohydrate

I will try, if I have time, to only melt the stearate in the glycol, add some triethyl citrate and some usnea barbata, PS 20 and some FO and see what happens

If I pack this antiperspirant in an airless tube and apply it with my fingers, all goes well! but I'd love to have a stick :D

thanks for the suggestions! I am not giving up!

Anonymous said...

Hello! When it says 'alcohol', what type of alcohol is it? Isopropyl 99%?

Susan Barclay-Nichols said...

I use denatured alcohol from Voyageur Soap & Candle.

robdmccart said...

Hello - I am excited to roll up my sleeves and dive in. I have already picked up most of the ingredients, but I have a question about using alcohol in deodorants, what kind of alcohol? I've scoured the blog but don't see a specific type listed... Thanks in advance for your help and sharing your knowledge!

Susan Barclay-Nichols said...

Hi Rob! Look up! Waaaay up! (Okay, just one comment up...)

robdmccart said...

LOL. There must be different types of denatured alcohol?

Susan Barclay-Nichols said...

There are quite a few different types of denatured alcohol, which is why I specified that I use denatured alcohol from Voyageur Soap & Candle so one can look that up and see what is in it. If you're curious about the other versions of denatured alcohol, check out the Canadian regulations on denatured alcohol.

Elizabeth Aqui-Seto said...

Susan, I'd like to try making one of the deodorants listed on your blog, but having the hardest time locating sodium stearate. I've searched many of the suppliers in Canada, with no hits.
I found a supplier in GA in the US. Just curious to know where you purchased your sodium stearate?

Many thanks.