The key to creating any cleanser for dry skin is mildness. We want to use the most gentle ingredients we can and increase that mildness through the use of emollients, thickeners, and other ingredients. Before we get any further into this post, please take a moment to read this post - incorporating mildness into surfactant based products - and we'll continue in a moment...
Welcome back! As you can see, we need to start with a gentle to mild surfactant, add our amphoteric surfactant (cocamidopropyl betaine or disodium cocoamphodiacetate), and add our mildness enhancers. Let's take a look at those for a moment and see what might be good for dry skin.
Cationic polymers: We know dry skin benefits from cationic polymers like honeyquat or polyquat 7. So this is something we'll want to include in our cleansers.
Hydrolyzed proteins: Normally, we'd use silk protein in products for dry skin, but our goal here is to create a film (that's why they're called "film formers"), so we'll want to go with something like hydrolyzed oat protein. Or you could go for something like Phytokeratin that has a combination of proteins that will penetrate our skin and those that form films.
Emollients: We want to include water soluble emollients that will increase the moisturizing nature of the product, so we'll want to consider using ingredients like Crothix, glycol distearate, Cromollient SCE, Micro Caprol Express, myristamine oxide, and water soluble oils like water soluble olive oil (PEG-7 olivate) or water soluble shea.
Myristamine Oxide is a cleansing agent, emulsifier, hair conditioner, emollient, foam stabilizer, viscosity booster, and foam booster. Use at 5 to 20%. I buy mine at the Personal Formulator - I don't think I've found it anywhere else. It's really inexpensive compared to the other water soluble emollients and works very well. Remember, I don't work for and I'm not affiliated with any company that sells bath & body supplies, so this is just my humble opinion, not a sales pitch!
Humectants: We know how much dry skin loves humectants, so there's no doubt that we want to include these in great quantity in skin cleansers. But we won't bother with sodium lactate or sodium PCA as they are rinsed off when we rinse off the surfactant. Better to stick with glycerin, honeyquat, and the other non-wash-off-able humectants.
Anti-inflammatory ingredients: We can include some wonderful extracts to reduce the results of irritation in our products, like white willow bark, witch hazel, and aloe vera.
And finally, we need choose our surfactants well. The main ones I use for dry skin products are
- sodium cocoyl isethionate (SCI) as it has a creamy feeling while you're washing and a lovely feeling afterwards. You can use the liquid ammonium cocoyl isethionate as well!;
- sodium methyl cocoyl taurate (SMC taurate) or sodium methyl oleoyl taurate (SMO taurate), both of which are considered very gentle and moisturizing;
- polyglucose/lactylate blend, which is a combination of decyl glucoside and sodium lauroyl lactylate, both of which are considered gentle and ultra mild;
- sometimes disodium laureth sulfosuccinate, which is good for all hair and skin types as it is gentle; and
- definitely cocamidopropyl betaine, which is our secondary amphoteric surfactant that increases viscosity and mildness in our products.
You're probably wondering why I'm not using decyl glucoside, especially considering it's such a gentle cleanser. The main problem with it is the pH. It has a very high pH - sometimes as high as 11 - and if you don't have a pH meter with which you can measure your product, you run the risk of having a very alkaline product, and that's a terrible thing for dry skin. I have the same issue with disodium cocoamphodiacetate - its pH is very high, and if you can't alter your pH reliably, I'm apprehensive to suggest it.
You don't need to own all these surfactants. I'd have three in total as a minimum - cocamidopropyl betaine and two others you like. Personally, I'd go with SCI or ACI (ACI is definitely easier to work with as a liquid) and the polyglucose/lactylate blend if you want a really moisturizing product. (This combination is very very moisturizing - too much for oily skin!) If you want something moderately moisturizing and you want to make some hair care products as well, I'd go ACI or SCI and SMO/SMC taurate. If you can afford it, I'd get all three and the cocamidopropyl betaine so you can make pretty much any surfactant product you want!
The SCI and ACI are what pearlize this hand cleanser and make it so moisturizing!
All right! We have our list of things we'll need to include in our cleansers. Let's start tomorrow with a body wash suitable for dry skin. If you're the impatient type, here are some posts relating to dry skin cleansers...
Formulating a creamy foamer facial cleanser (adapted for dry skin at the bottom of the post)