Tuesday, January 22, 2013

Facial scrubs: Working on our surfactant base recipe - part 4 (thickening!)

If you feel lost reading this post, please check out the previous posts on working on our surfactant base recipe part one and part two and part three

One of the other things to consider for this facial scrub is thickening as it is going to be quite watery with 40% surfactants! We took a look at using glycol distearate yesterday, but there are many ways to thicken surfactant based products!

My favourite way to thicken a surfactant based product is to add Crothix (INCI: PEG-150 pentaerythrityl tetrastearate (and) PEG-6 caprylic/capric trigylcerides (and) water), which is an ester that not only thickens our product quite well, but it increases mildness and offers moisturizing! What a great addition to a facial scrub!

I like to use liquid Crothix as it is easier to work with than the pastilles because I can add the liquid to the product cold days after I've made it! I tend to make my product, add the fragrance oil, mix well, and allow it to cool until it reaches room temperature (or warm up if it's been in the unheated workshop for too long!). I generally add 0.5%, mix well (remembering that it will fall to the bottom of the container), add a little more, and so on until it reaches the viscosity I like.

Liquid Crothix is my preferred method of thickening, and it is the ingredient with which I have the most experience.

SAMPLE BASE FOR A FACIAL CLEANSER WITH PHYSICAL EXFOLIANTS modified to include glycerin, polyquat 7, Caprol Micro Express, and liquid Crothix
HEATED WATER PHASE
25% surfactant of choice
15% cocamidopropyl betaine
46.5% distilled water
3% polyquat 7
3% glycerin
5% Caprol Micro express

COOL DOWN PHASE
0.5% liquid Germall Plus

AFTER THE PRODUCT HAS REACHED ROOM TEMPERATURE BUT BEFORE YOU ADD YOUR PHYSICAL EXFOLIANTS
up to 2% liquid Crothix

You can use a variety of thickeners - some will offer moisturizing and conditioning, and some might not. You can use gums like xanthan gum or guar gum or use thickeners like HPMC to thicken your products. Gelling agents - carbomers like ETD2020 or Ultrez 20 - can thicken our products very nicely as can products like Amaze XT.

Note: I have used carbomers and Amaze XT extensively. I have limited experience with the other three thickeners. As with just about everything else, you'll have to play with the amounts to see what works best for you. 

With xanthan gum, use it at 0.1% to 0.3% in the heated water phase of the product.

With guar gum, we need to hydrate it before using it in our products, so it's suggested that you sprinkle the guar gum over your room temperature water phase, stick blend or mix well, then leave to sit for about 15 minutes or so or until it is well hydrated (you'll be able to tell because it creates a gel). Then you can add your other water phase ingredients like aloe vera, hydrosols, proteins, and so on and heat and hold as usual. The usage suggested ranges between 0.3% to 5%, so you'll have to do some playing to figure out the best usage for your product.

With HPMC, you can thicken surfactants that would normally not thicken with with salt - things like decyl glucoside - and it's recommended that you sprinkle it into cold distilled water and add it at the end of the process with the cool down ingredients. (Make sure it is distilled water because we don't want beasties or other contaminants in our products!) Use it at 0.2% to 0.5% in surfactant based products.

With carbomers, please read the post as the process is quite important!

With Amaze XT, use it at 1% to 2% in the heated water part of the product. It is soluble in water and alcohol for creating gels. You can't use paraben based preservatives with Amaze XT based gels, which means Phenonip and Germaben II are right out. You can use liquid Germall Plus, Optiphen ND, and Tinosan SDC without problems.

SAMPLE BASE FOR A FACIAL CLEANSER WITH CHEMICAL EXFOLIANTS modified to include glycerin, polyquat 7, Caprol Micro Express, and Amaze XT
HEATED WATER PHASE
25% surfactant of choice
15% cocamidopropyl betaine
41.5% distilled water
3% polyquat 7
3% glycerin
5% Caprol Micro express
2% Amaze XT
5% AHA

COOL DOWN PHASE
0.5% liquid Germall Plus

Note: Amaze XT likes to be between pH 4.5 and 6, so if you are using AHAs in the product, make sure you have a way of testing the pH and alter it to be in that range!

Wow! We really have a recipe going here! I think we have a nice base here that contains humectants, surfactants, moisturizers, thickeners, and re-fatteners. And I think we've gone over a number of ways we could alter the recipe to include ingredients you really like! So what's next? I think we need to consider what extracts, hydrosols, proteins, and other things we could add to the facial scrub tomorrow! Join me then!

Related posts:
Summary on building viscosity in surfactant based products
Surfactants and how they react with fragrances

1 comment:

Julie said...

I have been following this blog on facial cleanser and I am slowly formulating the recipe I want to try based on the ingredients I have on hand. I was reading the description of Amaze XT on the Voyager website and then I was reading this post and a question came to me (I am not a chemist so hopefully this question is not too stupid). Amaze XT is described as an anionic polymer and I was thinking of adding polyquat 7 (for mildness and making the product easier to rinse),which you describe as a cationic polymer. Since one is negative and the other positive and both polymer, do they cancel each other's effect? In similar terms, is there any "goodies" that we add to our product that either enhance or negate each other?
Thanks for your science.