Monday, September 20, 2010

Esters: Polysorbates

Yep, polysorbates - like polysorbate 20 and 80 - are esters! They're ethoxylated sorbitan esters, which means they start off as sorbitan and are esterified, then they are reacted with ethylene oxide to create a non-ionic surfactant with a water loving head and lipophilic tail. You might find them as "tween 20" or "tween 80", which means they're derived this way, or "span 20" or "span 80", which means they're esters of non-PEG-ylated sorbitan esterified with fatty acids. (I'm not covering the span series of polysorbates here because very few of us use them!)

So what does the number mean after the "polysorbate" part of the name? It doesn't designate the number of oxyethylene groups found in the molecule like it does with the other esters because each polysorbate has 20 oxyethylene functional groups in the molecule. It indicates the type fatty acid used as the base. Polysorbate 20 is monolaurate, polysorbate 40 is monopalmitate, polysorbate 60 is monostearate, and polysorbate 80 is monooleate. These are all based upon the various fatty acids - lauric (C14), palmitic (C16), stearic (C18:0), and oleic (C18:1). They have different things they can solubilize and that's based upon the originating fatty acid. 

These are considered to be non-ionic surfactants in that they have a hydrophilic head and a lipophilic tail that can solubilize ingredients that wouldn't normally come together. (A solubilizer aids in dissolving ingredients that wouldn't normally otherwise dissolve into each other.) As we know, water and oil don't really like each other and will eventually separate into layers of oil and water that need to be shaken. By adding polysorbate 20 or polysorbate 80 (the most common ones we find at our suppliers), we can include something like a fragrance or essential oil (polysorbate 20) or a carrier oil (polysorbate 80) into our surfactant or water based products. Polysorbates will emulsify sebum, so they are also considered to be very very mild non-foaming, non-lathering non-ionic cleansers, which you can include in oil based cleansers, and they will increase the mildness and reduce irritation in surfactant products. They will suppress the foam slightly, so they're not suitable for low foamy surfactant products, but we can use them to suppress foam in things like facial cleansers, where suds and lather aren't welcome! 

Polysorbates are readily biodegradable and polysorbate 60 and 80 are acceptable food additives (look at the Twinkies package next time you snarf one down!), and they are considered non-comedogenic, so you can use them in your facial products! 

Polysorbate 20 has an HLB value of 16.7 and can be used as a solubilizer for fragrance or essential oils. We can use it in combination with a low HLB emulsifier (like glycol distearate) to create an emulsification system, or we can use it alone in water or surfactant based products to incorporate fragrance or essential oils (like toners, body washes, and so on). 

Polysorbate 20 is soluble in water and glycerin, partially soluble in fractionated coconut oil, IPM, and mineral oil. 

Polysorbate 20 has an HLB value of 15 and can be used as a solubilizer for fragrance and essential oils as well as carrier oils. We can use it in combination with a low HLB emulsifier (like glycol distearate) to create an emulsification system, or we can use it alone in water or surfactant based products to incorporate fragrance, essential, and carrier oils (like toners, body washes, and so on). 

Polysorbate 80 is soluble in water, partially soluble in fractionated coconut oil and soy bean oil, and insoluble in glycerin.

You can see the tail on the polysorbate 80 is much longer than that of the polysorbate 20 - this is thanks to the longer fatty acid used. Monolaurate has 14 carbons, whereas monooleate has 18 carbons with one double bond in the middle. 

To sum it up, we generally use polysorbate 20 for essential and fragrance oils - I use it in a pinch with some of the lighter oils like fractionated coconut oil or IPM when I'm out of polysorbate 80 - and we generally use polysorbate 80 for carrier oils. You can use polysorbate 80 for essential and fragrance oils, but you can't use polysorbate 20 for carrier oils. If you can only get one, polysorbate 80 is a good choice as it can do the job of polysorbate 20 as well as its own!

Join me tomorrow for more fun with polysorbates and other esters! 


Anonymous said...

Hi Susan,

Love your blog. Is polysorbate 80 soluble in honeyquat?

Anonymous said...

Hi Susan !
My name is Francis . I am particularly interested in your blog . Your article about Esters: Polysorbate is very helpful to me. Please give me some advices on :
1/ What temperature of water is suitable for the solubility of Polysorbate 80 ? of course higher water temperature causes fast solubility , but the chemical structure of product is also broken.
2/ How to dissolve PEG 4000 and Polysorbate 80 efficiently in water .

Please reply me. Your kind attention would be greatly appreciated.

Susan Barclay-Nichols said...

Polysorbate 80 is a solubilizer, so you can use it in water soluble or oil soluble ingredients. Honeyquat is water soluble, so you could mix it together.

Hi Francis. I've polysorbate 80 in cold water and had no problems, but warmer water is generally better. I've never used PEG 4000 so I can't make any suggestions, and I'm not really sure what you mean by dissolving polysorbate 80 in water. I just weigh it out and mix it into the water with the oils I'm using. Can you be more specific?

Tara said...

Arrrghh! I keep finding out about ingredients being insoluble in glycerin AFTER I make them! PS 80 and Cromollient!. It's terrible because I almost use glycerin in every surfactant formulation. Poo! (And by "Poo", I mean "poo", not "shampoo", lol!)

FRED said...




Anonymous said...

Do you know why Tween 80 (Polysorbate 80) that you can by from Sigma Aldrich says "polysorbitan monooleate has only 70% of oleic ester and the rest are "other" esters"

papi said...

Hi Susan & welcome from your vacations! Hope you have an easy adaptation :)
I know that this is an old post but I have a question(well..two!) about polysorbate 80..
The problem with me is that I do not know the usage percentance, I always use it how much to use??
Also, we use Poly80 in products with higher percentance in water and less oils, that's ok for me. My last question is that can we use it in products with higher percentance in oils and a bit of water? I use ewax in such an example and didn't work.. So??
Make a post about anti aging ingredients and how they work in that. :)


Nedeia said...

Dear Susan,

I have not used polysorbates 20 or 80 until last night, when I have used polysorbate 20 in a body scrub. I have followed the recipe's instructions to use it at 20%, which seemed quite high to me!

My question is: how to I calculate the amount of polysorbate in a product? are there recommended ranges? is there something like too much or too little?

also, are they interchangable?

Anonymous said...

Like Francis (March 26, 2011), I'm having problems when trying to dissolve Tween 80 in water solutions (without oils). Some polysorbate stays insoluble as a lump. And I'm afraid that hot water would produce peroxides in the solution. Do you have any expierence in situations like these. Do you know how to avoid these problems? Thank you very much. I hope hearing from you soon. regards, Belén (Argentina).

Georgette said...

I had the same with Polysorbate 80 lumping, but I was using Fragrance oils in the product.

Anonymous said...

Belén, I use Tween 80 in the lab> I use a magnetic stirrer(@ high speed) at room temp for 2 hours.

Anonymous said...

Hi Susan
I wish to make a water soluble massage oil. I am using safflower oil with 20% polysorbate 80. but I get a milky result.
1. is this the correct way to do it? how can I avoid separation?
2. How can I blend 50/50 water and oil and end up with a clear product for massage.
3. or how can I make a massage oil/product soluble in water?
the reason for my inquiry is that the oil non-soluble products stains/ruins the sheets.
thx a million

Susan Barclay-Nichols said...

Hi Brian. You can't make a clear emulsion, and that's what you're trying to do here. If you're trying to incorporate 20% oil, you really need to use a proper emulsifier instead of a solubilizer. Take a look at some of the water soluble esters. That's how my massage therapist's oils are made.

Unknown said...

Hi Susan,

I am trying to make a water based perfume spray from Agarwood oil,can you suggest if i could use PS20 to the mix and also if you may, please tell me how to make the mixture non-cloudy/milky?

Appreciate your blog on esters; its really helpful. God Bless You!!

Susan Barclay-Nichols said...

Hi Unknown. Have you looked up the posts I've written on other solubilizers? I think that will give you an idea of what you can do and what might work. In short, you probably aren't going to get a clear mixture using polysorbate 20. But look up those other posts. Look to the label "solublizer" for other posts.

Unknown said...

Dear Susan,

Thank you so much for your prompt response to the above query.

As you suggested I did check the other posts but was almost lost. I have been trying hard to find the way out of the cloudy result of the mix but gosh! its too damn adamant.
Although i have not tried PS20 but shall soon try it. Susan, if you come across any solution to this PLEASE share it with me.

Appreciate a TON...!!


Anonymous said...

Hi Susan

We are formulating our own brand of skincare products and need to add citric acid to balance the PH and add Polysorbate20 as a preservative to our toners to increase the shelf life.
Do you think that you could recommend a percentage for these two ingredients?

These are to percentages as it stands at the moment:

Roman Chamomile floral water 47.5%
witchhazel floral water 47.5%
glycerin 3.0%
cedarwood (male) and lavender (female) essential oils 2.0%

what do you think the percentages for the polysorbate20 and citric acid should be?

I have done loads of research but am struggling to find the answers so would appreciate if you have any for me.

Thanks you

Susan Barclay-Nichols said...

Hi Anonymous. Please put your name on your posts as we don't allow anonymous posts around here.

Polysorbate isn't a preservative; it's a solubilizer. What is the pH of the original recipe? How did you test it?

I can't stress enough how much you need to know your ingredients before you even consider selling your products. Please don't take this the wrong way, but I really don't think you're ready to sell. You need to learn more about the basics like preserving and emulsifying, and you need to leave your products for at least a year to see how they stand up over time before you can expose them to the public. You don't want to get sued or put out a terrible product that will smear your libe's name, so caution is the key here. I'm sure I'll be called out by someone who thinks I'm crushing your dream, but a foundation of the basic concepts of making products is essential, and I don't think you have that yet. Why not have fun learning how to master products you can share with friends before you think about this fabulous hobby as a business.

I know this isn't the response you expected, but it is the only one I can offer. If you do your research on preservatives, you'll get the answers you seek. As for pH, check out the posts with the label "pH" to find what I've written on the topic.

Ruem said...

Hi Susan,

My name is Ruem. Do you know if there's an ecological substitute for polysorbate 80? If so, I will appreciate to learn about it.

Thank you.

Amanda said...

I have a bottle of polysorbate 60 that has separated into two phases; is there a way to get it back together?

Susan Barclay-Nichols said...

Hi Amanda. I would worry that something has gotten into the bottle if it's separating. I have never seen polysorbate 20 or 80 separate before.

byronsown said...

Hi susan
Byron here
I have a recipe for making airbrush tattoo ink that requires Polysorbate 80. Any recomendations on micas???
or recipes of your own??

Bilalahmad Shafiq said...

Hi susan
my problem is just a quite simple i am making liquid dishwash
its okey transparent and enough density+viscosity
When i add D-Limonene(Brazil)it got mild and milky
kindly suggest better is polysorbate works to dissolve D-limonene ????
I already tried With Alcohol-mineral spirit, acetone al create a problem to me
kindly help me soon as possible.
thanks and bye
kindly respond to me At

Susan Barclay-Nichols said...

Hi Bilalahmad! I think the oil in the d-Limonene is being emulsified by the surfactants, hence the milkiness.

Jayce Liu said...

Hi Susan,

I've made a facial cleansing balm with a blend of carrier oils, added polysorbate 80 for the ease of washing the oils and thickened it with kokum butter. I'm very satisfied with the outcome so far but I'm having trouble finding a preservation method that will not be deactivated by the polysorbate in this recipe.

I live in a humid country, and I do not like the idea of having nasty stuff growing in the balm as I have a habit of handling facial products with wet hands.

I'm hoping that you will be able to suggest any preservative method suitable to be used or other solubilizer/surfactant that can be used instead of polysorbates to allow this balm to be preserved?

Recipe used:

Liquid Oils - 30%
Kokum Butter - 26%
Polysorbate-80 - 42%
EO Blend - 2%

Susan Barclay-Nichols said...

Hi Jayce. Check out this post that contains a few suggestions for preservatives.

JAC said...

Hi Susan,
Quite a few years ago my late sister ( a Pharmacist ) used to make an oil to rub over your body in the shower. It was wonderful. In my teenage years I think I used litres and Litres of it...... which infuriated my sister as it must have cost a bit to make. Gail has since passed away, but as I was unpacking some of her things to give away, I found her Journal. On the back page was a list of ingredients of this oil she called Summer Oil. I would dearly love to know how to combine these ingredients to make the same as she did. Just mixing them together does not seem to produce the same effect for me. Can you help. I just tried attaching a photo of her journal but it doesn't want to accept it. These are the ingredients (hoping I've read her words correctly) Mineral Oil/Isopropyl Myristate/ Acetylated Lanolin & Cetylaccetate/Acetylated lanolin alcohol

Then she says
E.O 1-2%
Rose Geranium
Ylang Ylang
Sweet Orange
If you could help me with this my daughters and I would be so appreciative.

Susan Barclay-Nichols said...

Hi JAC. Your ingredients are
mineral oil
isopropyl myristate (IPM)
acetylated lanolin
cetyl acetate
acetylated lanolin alcohol

You can see the lanolin related products here - Lubrizol, but I can't find a place for you to buy them. I think they may be essential to the product.

You could try your own with mineral oil and IPM and see what you think of it. I have a few recipes on the blog with this kind of body oil that I would encourage you to look at. Do a search for "body oil" or "isopropyl myristate" as that tends to be the ingredient that makes all the difference. I make a nice one with sesame oil or fractionated coconut oil and IPM and it's lovely.

Sorry I couldn't be more helpful.