gfeldman
Forum Replies Created
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I would highly recommend reading the “INCI Nomenclature Conventions” as a new cosmetic chemist (in particular Alkoxylated Materials). I found it very useful myself. It will give you a greater understanding of what you are actually looking at.
PEGs under a MW of 600 are liquid at RT (PEG-12 and below). Above PEG-12, for the most part all of the PEGs will be solid. The higher the number, the more substantive feel you will likely get from it. All PEGs are non-ionic and water soluble (for the most part) with lower MW PEGs being the most soluble. But, as @bobzchemist said, you really should read the literature on each one. Varied substrates can be modified with PEGs and it makes a drastic difference on their overall properties. Another source about PEGs that I suggest reading is “Polyethylene glycols and the pharmaceutical industry.”
Finally good luck and hopefully this information is helpful to you.
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Yes. Polyquaternium 37 is also a polymer. I don’t know what was going through my head when I mentioned that one.. the prefix “poly” kind of gives it away!
Ignoring that embarrassing mistake, I am still curious about alternative methods to thicken formulas. For me it is more of a fundamental desire to learn how thick lotions used to be made before common polymeric thickeners such as carbopol. I would like to be able to do the same. Although, yes I do know that carbopol is the best choice 9.9/10 times.
Much to my surprise though, I was in Bath and Bodyworks the other day and ran across a lotion that appeared to be only thickened with Cetearyl Alcohol, Cetyl Alcohol, and Ceteareth-20. Acrylates, gums, or poly”x” were not mentioned anywhere on the ingredient listing. Perhaps this would be a good approach for me to follow?
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Thank you for the suggestion! To be honest though, its not a problem in my formulas
I love silicones. My colleague on the other hand works with Silicone free formulas. I am also concerned about the source of the whitening. Do you know what causes it? -
No. I am absolutely not committed to Polysorbate-20. I also happen to have Pemulen TR-2 on hand. I tried a couple of batches today with it and didn’t have much luck. Not because of the Pemulen, I just think that my formulas were not up to par. I’m trying to make a cold process formula that is rather thick (thick lotion, not hair gel thick) at low pH’s (4). I think I got a bit carried away though because it ended up looking and feeling like snot.
Here is my somewhat simple formula:
A)
Water
0.1%EDTA
5% Glycerin
1.5% Aluminum Starch Octenylsuccinate
0.3% Xanthan Gum
0.3% Guar Gum <- this combined with the xanthan is what i think gave it the terrible feel
0.5% Ultrez 30
5% sunflower oil
0.25% Pemulen TR-2
C)
Neutralize with NaOHThen add citric acid back?? <-I didnt get this far as I have never worked with Ultrez-30 and I didnt feel like checking the pH as it already looked like snot.
What do you think, any advice?
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I am aware of the HLB system and I understand the calculations. Familiar might be an over exaggeration. Polysorbate-20 is high HLB (16.7). So I would need a low HLB emulsifier to pair with it (also one that is liquid at RT). Do you have any suggestions?
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@milliachemist & @Bobzchemist What concentrations would you typically use to form a “high” thickness emulsion? I am guessing 0.3% for Xanthan, but I have not worked with HV or CMC before. (Thank your for your suggestions!)
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@mlndeb Please do not post off topic questions. I am certain that the community would be glad to help you answer your question, but it will not get well addressed in this post and it can derail constructive ideas.
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@Gustavo Are you suggesting that you would like to inhibit the peroxidase enzyme? That would prevent the breakdown of harmful peroxides, thus causing increased oxidation (aging) in the skin. I believe that perhaps I have misinterpreted your question. Would anyone else like to weigh in on this?
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It seems unlikely that bound L-ascorbic acid would not disassociate during HPLC analysis (due to organic solvents involved, ect), but not having worked with bound Vit C in the past I cannot say for sure. What I can say is that if you degrade the proteins with high heat and/or 6M Guanidinium chloride they will unfold, releasing any bound L-ascorbic acid. Assay the solution again after doing so and you should be able to find out for sure.
(^^ If you want to go through all that trouble, otherwise use a vendor that is more upfront with you about the materials you are working with)
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@bobzchemist thank you for this fantastic list of links!
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@MakingSkincare Yes, it is a hot process emulsion. Cetyl alcohol could be used, but I have never tried thickening an emulsion purely with Cetyl alcohol. Would that hold up over time? What percent would you use? Also, I’m sorry for being so vague… extenuating circumstances
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@vitalys: Thank you. I am familiar with Lubrizol products, but I took a look at the website again anyways and it appears that they have a new product “Carbopol 30” that may be a perfect candidate.
@MakingSkinCare: I have worked with acrylates such as Carbopol, but those traditionally do not function well at lower pH’s. I have also worked with Simulgel, but that is rather expensive. Additionally I have worked with a few gums (xanthan/guar), but I’m really not sure what the best system would be for this type of formulation. I am very interested in hearing more about using fatty acids/alcohols as thickening agents. Would it be cost effective and stable over time?
@milliachemist: This product is intended for skin care / moisturization. I’m sorry that I cannot be more specific, but due to extenuating circumstances I do not feel comfortable revealing further details.
Thank all of you for your comments and suggestions. I am still (very) new to the field, but I’m trying to learn as much as I can and this site and its dedicated members have been nothing but helpful. Thank you!