[lewhitak]

I have previously used a powdered extract of purified green tea EGCG, which turns brown over time as well. The only thing that mitigated this was sodium metabisulfite and low pH. I was worried about the irritation potential of the sodium metabisulfite, so it was never fleshed out into a product. 

[lewhitak]

Regarding the N-Acetyl Glucosamine -

I’ve used a serum containing 4% Niacinamide + 2% NAG and it was nice, but not necessarily groundbreaking. I believe the goal was to offer a less irritating method of achieving similar results to an AHA without the low pH and sun sensitivity. I felt like my skin looked better and tolerated the product well, but that is entirely anecdotal.
However, as @ngarayeva001 wrote, the paper wasn’t independent research and I haven’t looked anything up recently to see if more has been done with it since it is patented. 

[lewhitak]

@Pharma haha! Totally agree, I have come across nothing that replicates the feel.

I’m stuck in my current project which requires no silicones but the expectation on skin feel seems to be based on creams which do contain silicones! It’s driving me up the wall. 

I will check those out, it would be amazing if they work in my application! Thank you. 

[lewhitak]

@Perry do you have a favorite silicone alternative? 

[lewhitak]

Ohhh, ok. I like that @ngarayeva001 - “buffer predicts the pH.”

How I get confused is in the case of buffering to stabilize an ingredient. For example, if a material is said to be stable using a pH 4.0 lactate buffer BUT after you add all the additional ingredients to the system you are more at a 4.5 or what have you. Do you then have to re-adjust to a pH 4.0? This is all theoretical, I haven’t tried it because I was unsure of what I was doing.

Thank you as well @EVchem!

[lewhitak]

Could you post some more information? You could theoretically reduce the phenoxyethanol and replace the lost activity with another preservative, but you need to consider a few things:

- pH of finished product
- leave on or rinse off application
- other ingredients in the formula
- whether the replacement is active against the same microbes as       phenoxyethanol

As always, when changing the preservative you will need to do PET to determine if the changes made still maintain an adequate level of preservation.

[lewhitak]

Well, I think Humblebeeandme is very much a DIY blog and should really be treated as that. The author is very clear on that as well. She does an awesome job at creating DIY recipes for home users but I wouldn’t expect in-depth chemical stability analysis from a DIY blog. That is a bit of an unfair expectation to put on DIY since it is supposed to be useful for any home user versus chemists or industry professionals. 

[lewhitak]

There is Eumulgin SG (Sodium Stearoyl Glutamate) by BASF and a few options from Roquette (DS 146 comes to mind) that are EO-free. Sepinov has an EO-free polymer called Sepinov WEO.  

[lewhitak]

@ajw000

TEA didn’t work for me with carbomer 980 in a 70% ethanol product. The polymer started to salt out. AMP did work just fine. 

[lewhitak]

I have a 70% EtOH hand sanitizer formula using 1% Carbomer 980 and we have issues with balling while rubbing the gel on your hands. Very nice gel, though-clear and thick.

Neutralization is done with AMP. 

The Carbomer 980 isn’t rated highly by Lubrizol on their comparison charts between the carbomers for not having issues with fish eyes/balling, so that might factor in to your choice. 

We had bulk in 980, so that’s why I ended up using it. However, I could definitely be missing a step here! Maybe a processing change would help with this.

[lewhitak]

This is a slower method, but heating a metal putty knife and running unsightly lip balms along the surface can help smooth things out. I do agree that the better option is playing with fill temps, though.

[lewhitak]

When incorporating shea butter into a previously cooled cream, rapid movement and quick cooling are important. Previously, I have seen it work when a food processor was used. Melted shea butter was slowly poured in while the cream was mixing. Afterwards, the cream was placed in a freezer or fridge to cool. Issues with shea graininess were never seen, but maximum usage for the shea was < 3%.

Your base cream will need to be tested for stability compared to the original, and you won’t know if your base can withstand this type of mixing until you apply it. The addition of more oils/butters may also pose a problem.

The easiest starting point is to add a bit of extra oil to the base and see how it does. Shea comes with a set of problems which you don’t need when finding out the limitations of your base.

[lewhitak]

Personally I have experienced sticky skin sensations from proteins.

[lewhitak]

@MarkBroussard What is a Freedom Formula? Is that another way of saying free from?

[lewhitak]

@Perry Good point!

@Bill_Toge Very true as well. There are many things I have learned on the job that I never would have been exposed to otherwise in an academic pathway. 

 At least her packaging is interesting….

[lewhitak]

It’s odd that she speaks down on the ability of a chemist to know biology. Just because a person has a degree in chemistry doesn’t mean that they don’t know how to research, read literature, and come to conclusions that are scientifically sound. That is rather elitist, and I’m a person whose background is biochemistry not even chemistry…

[lewhitak]

Glycerol increases protein stability and solubility when creating protein solutions in the lab.

[lewhitak]

Belassi, do you have any information about the green tea being an indicator? That’s very interesting. We use a 90% EGCG standardized green tea extract and I would love to learn more about it as an indicator. Thank you!!

[lewhitak]

I’m pretty certain that’s due to the pH of the ascorbic acid in solution, but I could be wrong. Once the pH of a solution is low the conversion of niacinamide to nicotinic acid is accelerated. Nicotinic acid can cause facial flushing, so it’s not desired in a formula. 

[lewhitak]

Well, if you’re seeking an effective licorice extract the concentration of glabridin needs to be fairly high. Purified glabridin is very expensive, but it’s the active constituent in licorice that can lighten skin.

[lewhitak]

The flawed rating system and rabid fan base who solely research things from EWG and take their word as law has made me severely dislike it. 

[lewhitak]

I’ve worked with dry algae powder and the color of our finished products has been very stable. We don’t use an emulsion base, however. I would see if you can find an extract from another supplier, if possible, and see what color changes you get. Also, maybe check the species of algae that you are using as this could possibly be relevant.  

[lewhitak]

I can’t find my source for this at the moment, but I believe that the hydrolysis reaction of nicotinamide has such a slow rate between pH 4-6 that it should be fine when one considers how long the product will take to use up, shelf life, etc. 

Also, as said by Bill_Toge, there are no strong acids or bases present.

[lewhitak]

I have used it at amounts up to 4% and haven’t noticed any noticeable increases in viscosity other than a slight ‘thickened’ feel to the serum (which occurs at 1% concentration). It feels quite nice on the skin, though! Also, formulation searches show usage of a traditional thickener like a carbomer or cellulose even when xylitol is present. 

[lewhitak]

Straight pullulan in small quantities (0.1%) makes for a nice subtle tightening with a smooth product feel.