[alchemist01]

Perry said:

There are lots of skin protectants out there but if I recall correctly Dimethicone and Petrolatum would work pretty well as barriers. (for example)

That product specifies water-soluble irritants, which doesn’t seem to apply to tear gas according to previous comments. 

[alchemist01]

Yes, I have used a slightly modified double can tumbler (commonly used for paint) to mix 5 gallon HDPE jerry cans.

This was to mix silicones, water, and some emulsifier for a personal lubricant being shipped out in the jerry cans themselves. I haven’t tried to use an overhead stirrer in one of these jerry cans so I can’t comment if it works better or worse, but I can say that for my specific purposes the tumbler worked.

[alchemist01]

Buying a substantial quantity of deuterium might put you on an FBI watchlist

[alchemist01]

err +/-1% of the value, not 0-2%. So if you’re pouring 1g like in your example, you could allot a range of (.99*1)-(1.01*1), or 0.99g - 1.01g. 
To be clear, the range you allot is for a QC department to tell you or your own standards, not me, 1% was just an example.

[alchemist01]

This is one of the reasons measuring by weight is useful. Measuring exactly 100mL of something viscous like glycerin means little if it doesn’t get into the end product.

I would recommend either:
a) adding whatever you’re weighing directly on the scale. If you’re making 100mL, just throw the beaker on the scale, TARE, and add 1g into it. This completely eliminates loss between containers.
b) weigh-by-difference. If you have a small beaker of Optiphen that has a net weight of 50g, pour from it until it weighs 49g. An easier way to do this is put your container on the scale, TARE, and remove so that the scale reads a negative value of the sum of the container weight and the ingredient weight. Pour out what you need, and put it back on the scale, effectively adding back the container weight. The negative value on the scale is how much was removed. This is particularly useful when doing multiple pours from a single container which has residual fluid that may be poured out with what you weighed and lead to over-pours. 

Also, allowing yourself a +/- range of 1% or so will make life easier.

[alchemist01]

I don’t think I can directly speak to precipitation, but I have made many batches of a product that uses both xanthan gum and HEC.

HEC will hydrate well enough on its own over time, xanthan is kind of a pain. I recommend using shear mixing if possible, and giving it plenty of alone time with water, which would mean adding it prior to surfactants. It sounds like in both your methods you add it to the end. 

This is just how we’ve used it. I have never seen precipitation. I don’t know if it provides the best texture for a face wash… sort of more slimy. If possible I think the best way to get a thick cleanser is still anionics and salt.

[alchemist01]

Your oil phase has waxes, so I imagine you’re heating it pretty high. Do you add the preservative in with heat or do you let it cool?

I’ve seen similar goop with phenoxyethanol (in Optiphen) when I carelessly added it above 100C.

[alchemist01]

Devansh7 said:

Also any source to know what blend would be the best with absolute certainty? 

I highly doubt anyone will tell you that, because no one has made your product.

[alchemist01]

esthetician922 said:

Thank you! Actually, to piggy back this question. If one didn’t want to use Propylene glycol what would be a good substitute?

What are you using it for? Propylene glycol is a multi-faceted ingredient.

It works as a humectant, so you can substitute with glycerin, sorbitol, PCA, etc. if you need one added in.
It also works as a preservative enhancer, so you could replace it with ethylhexylglycerin.
It enhances skin penetration to improve active efficacy, I’m not sure what some alternatives to that could be as I haven’t utilized that aspect of it.
It also works as a solvent in some systems, and can be replaced with whatever applies.

If you’re looking for a general replacement that hits most/all of these, I think propanediol, butylene glycol, pentylene glycol (noticing a pattern?) all work similarly. However, propylene glycol works great and is very cheap so I’ve never bothered. 

I would identify what the role of propylene glycol was initially and figure out how to appropriately replace it.

[alchemist01]

em88 said:

The homogenizer (if it has enough power) should be able to disperse carbomer in the fluid mass, while the mixing paddle should mix carbomer with the neutralizer and form the gel. 

@alchemist01, your process needs to be optimized. You are wasting 12 hours. 

It’s actually quite an efficient process. It’s not worth it to me to use a homogenizer and dispense into final containers, as I can hydrate/mix/neutralize the gels in totes and ship them out as is. I would argue that it saves a lot in the long run as far as maintaining and cleaning a mixing tank goes. The 12 hour downtime only costs me a corner in the warehouse where they’re stacked.
I understand my situation is kind of unique, though, so it’s hardly a method for everyone. Rather, I was elaborating on how with 940 you don’t need high RPM mixing at all, if you invest time. 

[alchemist01]

nielrobertlim said:

@alchemist01 What is the rpm of your paddle mixer?

I use a mount mixer that mixes everything in its final container (a 1kL tote), but I would estimate about 150-250rpm for 30 minutes for the carbomer mixing.

[alchemist01]

ngarayeva001 said: Retinol is a very serious ingredient and should be treated accordingly. 

No doubt!
Read this if you have any doubts: https://animals.howstuffworks.com/mammals/eat-polar-bear-liver.htm

[alchemist01]

This is what we do in our production of 1000L gel batches:

1) Add carbomer into a dry vessel
2) Add water on top, and try to make an effort to wet all the carbomer so that no dry “islands” poke up
3) Give it a good, low shear mix until homogenous
4) Store overnight (12+ hrs)

In the morning a visual QC check confirms hydration and that batch can be used.

[alchemist01]

My company makes what is basically Icy-Hot and we tried out menthyl lactate, methyl salicylate, and menthol. 

I don’t recall specifics about menthyl lactate but for what it’s worth it made a lot more sense for us to use menthol. It works quite well functionally and was already something we had in supply and is relatively cheap. 

[alchemist01]

It’s not that they won’t “mesh,” it’s that hyaluronic acid is water soluble. To incorporate it into your formula, you need water.
That said, sodium anisate is also water soluble, and probably isn’t great as a sole preservative, though without water you don’t necessarily need one.
Your rosemary extract also has a good chance of containing water, so it would violate your anhydrous concept at the least, and totally not mix with your oils either.

I’m also not sure if this is a “cream” without an emulsifier so much as it is a “body butter” or something… though that may just be semantics.

[alchemist01]

What are you asking for exactly? It appears you copied this product’s ingredients: https://ondabeauty.com/products/rejuvenatingfaceandneckmoisturiser
If you’re trying to recreate their product, wouldn’t you know if it works or not?

[alchemist01]

The extract in question is lobelia inflata, for what it matters. I agree homeopathy is nonsense, but this particular extract is contributing a lot to the color/scent of their product, which is of more interest to me than its function. Reading more on it, I guess there’s very little chemistry to homeopathy as the definition of “1X” changes from source to source.

The product I’m replicating is actually an OTC drug and under actives it says “Lobelia Inflata 1X………………………….Pain, Inflammation.” How is that allowed?

[alchemist01]

I think you might get a lot out of this paper: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6099538/pdf/molecules-23-01571.pdf

[alchemist01]

I think that pH is a little low for a conditioner. I have no idea if that’s the issue, but it should be a quick adjustment to try. I would try and bring it closer to 4-5, but that’s a personal range. For a rinse-off conditioner cetrimonium chloride is usually more like 2-3% active. If you feel your product works well you can leave it as is (maybe whatever your honeyquat % is makes up for it), or change it once you resolve the stinging.

Maybe someone with more experience than I can pick out incompatibilities with your LOI, but if none of that helps you should just try cutting out ingredients one by one to pinpoint the issue.

[alchemist01]

I don’t think it’s too much, it’s probably too little.

What is the product’s pH?

[alchemist01]

@jemolian Would you mind elaborating on the slurry method?
I’ve been having trouble preventing agglomeration of carbomer without shear mixing in larger batch sizes. Indirect addition methods I’ve read usually use an oil phase, but anhydrous hydrophilic solvents (for oil-free formulas) seem to clump the stuff just as bad as water.

[alchemist01]

I made a version I quite liked with 4% PG, 1% PEG600, 0.4% Glycerin. It beat Purell in a blind trial with some office workers next door, too!
This was for 70%v/v ethanol, I imagine going lower or higher will give different results.

[alchemist01]

“Balling” is a common phenomenon with carbomer. Some formulas actually do it on purpose to create a soft exfoliant (http://colinsbeautypages.co.uk/skin-peeling-from-peeling-gels/).
From what I’ve read it happens because carbomer is hydrating with skin’s moisture on contact and create tiny gel clumps. This is usually because there’s too much carbomer in a formula, but I get the feeling that’s not your issue. You probably just aren’t letting it hydrate enough. I’ve been told a million different ways to go about doing that, I would just experiment with what works for you.

Also I recommend distilled water whenever possible.

[alchemist01]

@David08848 there is a blog post on this website that should help you figure out your salt curve.

https://chemistscorner.com/why-does-salt-thicken-shampoos/

[alchemist01]

Microbes can grow in salt solutions approaching saturation. I have no idea how much salt you’re adding but I would use a traditional preservative.