Tuesday, July 23, 2013

Making a Japanese themed body wash - surfactants

Why did I choose the surfactants I did for my Japanese themed body wash? Always ask yourself about your goal and skin feel preferences to determine which ingredients you'll use. I like to use at least two anionic (negatively charged) surfactants and one amphoteric (could be negative, could be positive) surfactant in my products because that kind of combination makes the product milder and thicker. I like to choose surfactants that offer gentle to mild cleansing, good lather, good foam, and ones that might be nice for oily skin.


12% cocamidopropyl betaine
10% ACI
6% polyglucose/lactylate blend
12% C14-16 olefin sulfonate

ACI (or ammonium cocoyl isethionate): Isethionates are considered exceptionally mild for skin, hair, and eyes, and are particularly tolerant to hard water. They leave behind a great skin feel - usually described as "silky" - and create really lovely foam, bubbles, and lather. ACI is substantive to skin, so it offers not only gentle cleansing and a creamy after feel, but it will offer some conditioning. Oily skin will benefit from the moisturizing without oils, while the dry type will appreciate the lack of tightness. Because it's a liquid, you can create clear surfactant mixes and don't need to worry about all that melting (although you'll still want to include the cocamidopropyl betaine for thickening and increased mildness). I'm using the liquid ACI instead of powdered SCI because it's easier to incorporate into my products.

C14-16 olefin sulfonate (aka Bioterge AS-40): The alkyl sulfonates are fantastic cleansers for oily to very oily hair and skin. They can be made much less irritating by including an anti-irritant like Crothix or glycol distearate (EZ Pearl) or by combining surfactants. I like a combination of BSB, Amphosol CG (cocamidopropyl betaine), and Bioterge AS-40 for body washes and shampoos. They are great additions to a bubble bath because they have great flash foam - the initial cascade of bubbles when you add it to the water. And they are great for hand washes because of that flash foam! They're great emulsifiers. So if you wish to include some oils in your surfactant mixture - essential or fragrance oils or a light oil like sunflower - you can do so up to about 2% to 3% without adding solubilizers like polysorbate 20 or polysorbate 80

Polyglucose/lactylate blend: A very very mild cleanser that offers moisturizing, a reduced feeling of tackiness, and a boost to the conditioning power of your product. It contains decyl glucoside, a very mild non-ionic cleanser that works well as both a primary or secondary surfactant as it is a good foamer, with an alkaline pH that can improve the cationic conditioning in your products and stabilize foam. Sodium lauroyl lactylate is considered an ultramild cleanser that is substantive to our skin and plays well with cationic polymers like polyquat 7 or honeyquat. It reduces feelings of tackiness. It is an emulsifier and moisturizer, so you should be able to add small amounts of oils - like fragrance or light carrier oils - without fear of separation.

Cocamidopropyl betaine: An amphoteric surfactant, it's never used alone in a formulation; you'll always use it as a secondary surfactant. It offers great foam stabilizing and a reduction in the irritant level of the anionic surfactants. It offers a great flash foam and some humectant properties. Because it behaves as a cationic in our products - because our pH should be below 7 - we find an increase in moisturization of our hair or skin and some anti-static properties. CAPB is a great thickener for alkyl sulfates (like SLS) or alkyl ether sulfates (like SLeS and ALeS). I always include it in every product for its ability to increase mildness and reduce irritation.

What does each ingredient bring to the mix?

  • ACI brings lovely lather, foam, and bubbles and an elegant, conditioned skin feel. 
  • C14-16 olefin sulfonate is good for oily skin and brings flash foam and lather to the mix. It also acts as an emulsifier for my fragrance/essential oils and emollients. 
  • Polyglucose/lactylate brings a very mild cleanser that offers foaming and foam stabilization as well as compatibility with cationic polymers and emulsification. 
  • Cocamidopropyl betaine offers foam stabilization and mildness, as well as some thickening. 

If I were to substitute one of these surfactants for another, I'd think about what the surfactant brought to the mix and what I could use instead.

If you have dry skin, you could substitute C14-16 olefin sulfonate for a surfactant that worked better with dry skin. C14-16 olefin sulfonate brings flash foam and lather as well as emulsification. We can get the foam and lather, and a lovely skin feel, from ACI and the emulsification from the polyglucose/lactylate blend, which means we could just up those other two things and get rid of the 12% C14-16 olefin sulfonate.

If you don't have polyglucose/lactylate, we could find another surfactant that offers the same qualities - mild cleansing with foaming and foam stabilization with emulsification - and substitute it. From the surfactant chart, I can see that SLeS, cocamidopropyl betaine, DLS mild, and the taurates are very gentle or very mild cleansers. SMC or SMO taurate offers the foam and lather we want, and it's good for normal to dry skin. This sounds like a great choice! It doesn't offer the emulsification, but if I'm leaving in C14-16 olefin sulfonate, we already have it there.

I never bother adding a solubilizer to emulsify my fragrance or essential oils as surfactants are, by definition, emulsifiers. I've never made a surfactant blend that didn't handle up to 3% oils, and I've found adding things like polysorbate 20 or 80 only makes the product less foamy and lathery. 

You might also want to consider how the surfactants thicken. This body wash is quite watery compared to my other ones, and that's because this blend doesn't really like to thicken with Crothix as much as something like SLeS, cocamidopropyl betaine, and C14-16 olefin sulfonate would thicken. Some will thicken with the inclusion of salt and some won't. (Lots of posts in this section on thickening surfactants). This is something to consider if it's an issue to you. I'm not really that picky about the viscosity as I don't sell my products, but a tiny change can make a huge difference!

I definitely recommend that you use at least two anionic surfactants to create a blend you like and the amphoteric surfactant. If you use a blend like BSB or baby blend or something else, you can just use one anionic and one amphoteric surfactant. But don't get too dependent upon blends! When your supplier stops carrying them, you're in trouble and will have to reformulate all your products. (I found this out with Bioterge 804 and LSB when Voyageur Soap & Candle stopped carrying them!) Choose the surfactants you use based on the qualities you want. You will have to play around with them to see which ones you like best.

If you're buying surfactants, I suggest getting small amounts of a few of them to play around with different combinations. You don't need much - get 250 ml or so of each one and make some products like shampoo or body wash or facial cleanser to see which ones you like the best. You might find you like different blends for different products.

As a note, every surfactant will cause irritation at some level, but some are higher than others. It is folly to say, as I saw in a recent flyer for my pharmacy, that this irritation of our eyes or skin indicates it is toxic. This isn't the case. Is baking soda toxic? Is milk toxic? If I put either in my eye, I'll be irritated. (Please don't try this at home!) Irritation isn't about toxicity, it's about pH and other components. So make sure you check to see the safe as used data about your chosen surfactant. 

As another note, when we talk about active ingredients in a product, we mean how much of the ingredient is what it says it is. Let's take C14-16 olefin sulfonate. If you look at the data bulletin for this ingredient, called Bioterge AS-40 by Stepan, you'll see it is 39.1% active. This means that 100 grams of Bioterge AS-40 contains 39.1 grams of C14-16 olefin sulfonate, the rest being water and possibly preservative. If you see that you can use up to 10% active ingredients before seeing eye and skin irritation, you know this means the active ingredient C14-16 olefin sulfonate can be used at up to 10%.. If you add 10 grams into your product, this means we have 3.91 grams of active ingredients. 20 grams - 7.82 grams active ingredients. 25 grams - 9.775 grams active ingredient. We can include 25 grams Bioterge AS-40 in our products and get slightly less than 10% active ingredient. All my recipes are written about the bottle of product - in this body wash, we're using 12% Bioterge AS-40, not 12% C14-16 olefin sulfonate - not about the active ingredient level.

If you want to learn more about surfactants, I encourage you to check out the surfactants section of the blog for more information. 

Join me tomorrow as we take a look at some other ingredients we can include in our body wash!

No comments: