Sunday, August 20, 2017

Weekend Wonderings: What's making my lotion sticky? (part two)

Yesterday, we took a look at a formula submitted by BrNy to see what could be making her lotion sticky. Today, we'll see what we can do to reduce that skin feel.

Here's the ingredient list again: Glycerin, resveratrol, n-acetyl glucosamine, water, sea kelp bioferment, niacinamide, dl-panthenol, allantoin, liquid Germall Plus, fractionated coconut oil, and Aristoflex AVC.

What can make your skin feel sticky? Glycerin, sea kelp bioferment, and Aristoflex AVC.

What can we do about them? Loads of things!

Glycerin is the big culprit here, but we need it to dissolve the resveratrol in something like alcohol, glycerin, propylene glycol, butylene glycol, or propanediol 1,3, to name a few solvents. Aristoflex AVC can handle alcohol - up to 50%, but I haven't tested it that high - so we know alcohol is an option. 2% alcohol to 0.5% resveratrol would work. You could do the same for any of the solvents.

I admit it - I'm having a torrid love affair with propanediol 1,3 as a humectant and solvent these days. It has a dry, almost powdery skin feel with no stickiness. I've been dissolving everything in it lately, from salicylic acid to resveratrol, and it works so well in that capacity. I've also been using it as a humectant in my cooling sprays, toners, and other places I really don't want a sticky after feel. It's awesome!

You can see it in action in this Gigawhite & Vitamin C moisturizer with Aristoflex as I dissolve 0.5% resveratrol in 3% propanediol, and it feels just lovely!

I'll be writing more about this later this week as I've just realized I don't have a post on this ingredient. What the heck???

When it comes to sea kelp bioferment, we don't have a load of options because we can't include hydrolyzed proteins in Aristoflex as it messes with the viscosity too much. You could leave it out entirely, or you could see how you like it with just the glycerin removed. I would reduce it down to 2% as that'll be enough for the film forming properties we want. 

With this little tweak, your formula would look like this...

LESS STICKY FEELING ARISTOFLEX AVC FORMULA
RESVERATROL DISSOLUTION
2.0% propanediol 1,3, propylene glycol, or denatured alcohol
0.5% Resveratrol

WATER SOLUBLE INGREDIENTS
81.5% Distilled water 
2.0% Sea Kelp Bioferment
4.0% n-acetyl glucosamine
3.0% Niacinamide
2.0% dl-Panthenol
0.5% Allantoin

OIL SOLUBLE INGREDIENTS
3.0% Lotioncrafter FCO

EMULSIFIER 
1.0% Aristoflex AVC

PRESERVATIVE
 0.5% liquid Germall Plus

1.  Mix the propanediol 1,3, propylene glycol, or denatured alcohol with the resveratrol into a small container, like a shot glass. Set aside for a moment. 
2. Measure distilled or de-ionized water into a container. You can heat it slightly - no more than 40˚C - to ensure the allantoin, niacinamide, and panthenol dissolve. 
3. Add your water soluble ingredients to the container, then add the resveratrol to the container. Mix with a stick blender for a few seconds. 
4. Add the oil soluble ingredients. 
5. Add the Aristoflex AVC. 
6. Add the preservative. 
7. Mix well. Bottle, and rejoice! 

So what did BrNy think? The batch I made turned a brownish color so i chucked it (could the resveratrol have caused the discoloration ?) and made a new batch sans glycerin or resveratrol and tweaked a bit. To that old recipe I added NAG at 4%, niacinamide at 2% and honeyquat at 3%. I love this new version of the lotion, it's NOT sticky at all and my skin saw good improvement in tone and texture since i started using it. In my experience making facial lotions, glycerin usually makes my pores look enlarged and it breaks me out so I'm leaving that out from now on. 

So it's a success with less stickiness by just switching out the glycerin. Yay! This is a great example how a small change can have a big impact on the skin feel of your product. 

Yes, the resveratrol could alter the colour of your product slightly. I've had this happen, too. 

Be careful when you're adding something like honeyquat to Aristoflex AVC. It's anionic or negatively charged and Honeyquat is cationic or positively charged, so they can interact and ruin the emulsion or the viscosity of your product. (I've done this before, and it's not a huge deal, just know that this can happen.) 


Before we leave this topic, BrNy asked another great question: Would sodium lactate or sodium PCA be good alternatives in lotions made with other emulsifier like Incroquat BTMS-50 (since Aristoflex AVC can't handle sodium?) Can they be used together in a lotion? 

I love sodium lactate so much - it's one of my favourite ingredients - but, as you mention, it can't be used in Aristoflex AVC. I love sodium PCA, too, it's one I don't use as much as I can't get it easily in Canada. So the quick answer is that yes, you can combine different humectants together to make something super hydrating! 

As usual, my brain spied a "shiny thing" in your question about humectants, and I've gone down the rabbit hole about humectants for a few hours. I'll be writing more about them later this week. Until then, join me tomorrow for an awesome cooling spray chock full of our lovely humectants as we continue the "It's too hot to craft!" series! 

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