[Learntounlearn]

Pharma said:

Mixing salicylic acid with betaine in water results in betaine salicylate (at a pH dependent degree).

Also, mixing salicylic acid with sodium citrate (mono-, di-, or tricitrate doesn’t matter) results in sodium salicylate and citric acid (or a corresponding citrate). Again, the degree depends on pH and molar ratio.

In the end, all that matters is pH which turns salicylic acid into a more or less water soluble salt and thereby allows for easier dissolution. In low % aqueous or even anhydrous preparations wherein salicylic acid is soluble, production of salicylate salts results (for most cosmetic ingredients) in a reduced solubility.

Can you please elaborate on pH dependency when solvent used is water and betaine. How does Increase or decrease in pH alter the solubility. Does a pH range of 4-5.5 results in a stable solution. 

[Learntounlearn]

Graillotion said:

You did not mention your other ingredients…but I am sure you are aware that it is VERY sensitive to electrolytes.  Really, it’s only drawback.  (Sometimes this (and pH) forces my hand…to use the jiggly ‘Zen’…hehehe, but keeping ‘Zen’ below .5% will make it play nice.)Graillotion said:

I always use it in the oil phase.  It does NOT dissolve in oil, so no amount of stirring or time will alter the state in oil.  I view this as a HUGE advantage.  If mixed into the water phase, then you are working with pudding….I don’t like working with pudding.

I have found that over time, as the Aristoflex AVC I am using is repeatedly exposed to moist air, each time I open the bag….it does start to clump as a raw material.  But even this will process out, with time, and especially a second stir.  Using equipment that gives some shear, will also help with this.

All of my products are warm process.

There was no luck in your process, it was designed to perform in your situation….or many others.

Aloha

Yes, I am aware of its instability with electrolytes. Thanks for mentioning the clumping issue. I was getting worried about it’s storage and suitability for further use.

[Learntounlearn]

jemolian said:

Normally powder polymers don’t melt, they just get dispersed. So if it’s fully dispersed in your oil phase, you can go ahead with the next step. 

After cool down, you don’t particularly need to blend again, it’s perhaps better to use a low shear option. If you are at home, just mix it by hand. Normally i just use an overhead lab mixer as i have one at home. 

Thank you. This is what I needed to know.

[Learntounlearn]

ngarayeva001 said:

Zen can deal with 1-1.5% of sodium lactate. But that’s about it. And it’s the most electrolyte resistant  polymer I have tried. I test them in water as @Graillotion suggested.

When manufacturers say ‘electrolytes resistant’ they mostly mean acid but not salts.

I am confused about this- To neutralize acids, base is added then salts form. Then does zen work for Aha based serums or creams

[Learntounlearn]

Graillotion said:

BTW….here is a quick example of how to test your polymerics and electrolytes:

Just mix the water, the Sodium Lactate, and the polymeric….shear it together, (at the levels you will formulate at) and observe for 24 hours.

Mystery solved.  My genius mentor says… if there is an incompatibility…it will manifest itself very quickly.

Thank you for Your detailed insight. 
One more qtn pls.. If I use emulsifiers that add viscosity and then include additional fatty alcohols, do I still add any thickener for better stability of end product? If the total oil phase is at 10%

[Learntounlearn]

Paprik said:

You should not use 3 rheology modifiers. They will only “ball” on the skin and feel terrible. You can stick to Sepimax Zen, this one is electrolyte resistant. However, it does take time to properly hydrate. So method is crucial - You would add that to a water with preservative and stir properly. It will look clumpy. Leave it overnight (or several hours) to properly swell. The next day you can mix it and start you process. Low shear only.
(Other gums are ok with high shear)

You are also missing antioxidant. Grapeseed oil does easily oxidise, so your cream would not last long time. 

Hope that helps  

Thank you so much!
I was just searching forum for help on preventing pilling /balling  your reply is a savior.

[Learntounlearn]

ggpetrov said:

You can’t use synthetic polymers together with electrolytes (sepimax Zen). The sodium lactate will broke the polymeric net of Zen. In this case, you should use only natural gums.

Zen is electrolyte resistant. I would have solely added zen but to be on safer side, I included gums and HEC

[Learntounlearn]

ketchito said:

@Learntounlearn I don’t think yoo need all three thickeners and at those levels. Usually one gum at 0.2-0.5% will suffice. The thing is that you need to add it in the water phase, at the start of the process, so it becomes part of the emulsion.

Thank you
I want it to be of cream consistency suitable for cream jars, as well as of light texture.

You mean to say add the thickeners to water phase and blend them in and then proceed with the heating of phases and mixing? 

[Learntounlearn]

Padmavathi said:

Carbomer works!
I usually prepare a 2% solution and keep (with preservative).  I add how much I need of this solution, post emulsification, depending on the viscosity I want, and adjust pH.
From what I have observed, the final product thickens the next day. So I’d say don’t add too much.

Hi, 
I always wanted to work with carbomers but the thought of neutralization of to form a gel holds me back. Your approach seems interesting so
  please explain how you prepare your carbomer’s stock solution.
What bases can be used?
Also does adding a 0.5% or above of this stock to an emulsified cream/lotion, thickens it?
Thanks

[Learntounlearn]

Perry said:

@Learntounlearn - Thanks for the heads up.  Yes, we are making some updates on the website and there is a link issue that is redirecting to that page.  Bottom line…we’re working on getting that fixed.

If only we were a big company. They’d have dozens of people working on the problem

Hi Perry,

I have previously bookmarked many discussions but now when I open them, it gets directed to landing page.
Is it possible to have a search bar only for forum topics as the available search bar on site works only for blog topics.
Thanks

[Learntounlearn]

@Thota yes, It did. However, when I used today which is after 5 days after making I didn’t feel the same urge to itch. This is not the first time I experienced this. That’s the reason I posted this question to know if polymeric emulsifiers such as sepinov and lecigel are to be left for a while after formulating. 
@JOJO91343 the one without Tamanu too had the same issue. 

[Learntounlearn]

Here are the formulas:

Water	83.878
Niacinamide	5.000
Propylene glycol	3.000
MSM	3.000
Sepimax zen	1.500
Sepinov emt 10	1.000
Licorice extract	0.500
Phenoxyethanol + EHG(Euxyl PE 9010)	1.000
Tamanu oil (refined)	1.00

With lecigel

Water	68.700
HA	10.000
Niacinamide	6.000
Propylene glycol	4.000
NAG	2.50
C12-15 Alkane	1.000
Lecigel	1.500
Squalene	3.000
Ceterayl alcohol	1.500
PE +EHG	1.000
Sepimax Zen	0.500

Used it before adding Sepimax zen and I felt the same-the urge to itch that persisted for few minutes

Also my skin is not sensitive to actives. Prepared the first formula with only sclerotium gum and didn’t have any such issues

[Learntounlearn]

Article on the same topic opens up when any link related to chemist corner discussion forum is opened for viewing. Sorry for posting here. But I hope Admins take note of the site issue. 
https://chemistscorner.com/misunderstood-motivations-of-big-cosmetic-companies/

[Learntounlearn]

Thank you so much. I never thought of this.

[Learntounlearn]

Hi
Thank you so much for your reply
My current batch came out perfectly but the problem is I don’t need to add anymore zen now but to make it to 100% I need to add 1.5 gms of water. Will it be ok to add the remaining water after the preparation has gelled?

[Learntounlearn]

ngarayeva001 said:

Not commenting on its skin benefits because papers I saw weren’t persuasive, but I managed to dissolve 4% in plain propylene glycol. It took an hour of stirring using a magnetic stirrer. Didn’t even had to heat it.

Can you pls share your experience wnen used in an emulsion after dissolving it in propylene glycol -Does it get oxidized or changes color of emulsion? 

[Learntounlearn]

Pharma said:

Your line of thoughts is spot on, susceptibility to oxidation is the main issue. Whether or not the added amount of BHT will suffice, only trial and error will tell.

From a theoretical physical point of view (emulsion stability), squalene in a o/w emulsion might be superior to squalane in some regards but may have a negative impact due to a lower melting point of the oil phase and therefore easier droplet fusion.

Just came across a paper on the o/w squalene emulsion.. Here’s an excerpt

“an unbuffered version of the squalene o/w emulsion MF59® experienced an unexplained loss in squalene content at 25 or 37 °C over a 3-month period”

MF59 - tween 20 and span 85. 

[Learntounlearn]

You mean the water within honey used determines the need for preservative and the quantity of honey that can be used within a formula?