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Formulating with Vitamin C
Hi everybody
I have a project on hands and would like an opinion of my esteemed fellow cosmetic chemists.
Is it possible to formulate a conductive water-based gel with 15% of ascorbic acid with final pH 3.0-3.5? This gel will be used with ultrasonic professional device (3 MHz).
Your thoughts?
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25 Replies
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Certainly. Ultrasound gel is really nothing more than water, carbomer and preservative. No problem adding functional ingredients to it.
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Normally Carbopols are useless at low pH. There is Carbopol Aqua CC, but I haven’t tried it and not sure whether it is approved for use in Australia. Good thought though. Thanks, will check it out.
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Agreed. At that pH, I would not use a Carbopol. Lubrizol does have one that gels at pH 4.0, but I forgot the name of it.
At the pH level you want to work with, I would go with Konjac Root Powder as the gelling agent. -
I have tried a sample of Carbopol Aqua CC in a different application (cleaning product with surfactants) at around pH 3 and didn’t have much luck with thickening at that pH but it might work for you at a pH closer to 4.
I am in Australia so I am pretty sure that Carbopol Aqua CC is approved for use. I’m not sure how much you would be looking to purchase but the distributor is Bronson & Jacobs.
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Thanks Ozgirl! The pH is likely to be around 3, not 4. I guess it is back to tried and proven Xanthan gum. It makes a sloppy liquid gel with 30% AHAs. I haven’t tried this formula with ascorbic acid but if I can’t find a better alternative, then I’m stuck with it.
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Mark,
I had to Google Konjak Root. Haven’t heard of it before. Looks like it sold in Australia as weight-loss supplement.
Have you tried it in the formula and at what levels?
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Yes, it is also known as Amorphophallus Konjac Root Powder or Glucommanan. If you use it around 1.0% it will form a nice, crystal clear gel, much like Carbomer. At lower percentages (0.2%) it will thicken like a serum and at 0.5% will form a thick gelatinous liquid.Better than Carbomer in my opinion since it has moisturizing and film forming properties and is stable over a wide pH range … 2 to 10 and quite tolerant of acids/bases, electrolytes.Pay no attention to the weight loss applications … it is also used as an ingredient in food products. Try to find 95% Konjac Root Powder.
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Great. Sounds rather promising. On my way to hunt 95% powder. Thanks again.
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Reporting back on a trial with Konjac Root. I have used Glucomannan 95% purity powder. Happy with the result. At 0.5% I got clear flowable gel with 10% ascorbic acid. Will continue work with this formula. Thanks, Mark for a great suggestion.
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Anytime, Galina. It’s a really nice ingredient!
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I would also like to say a BIG-FAT-and-BEAUTIFUL THANK YOU to the helpful experts (I think I learnt this from @Mark Broussard) on this forum, it was on this forum I learnt about Konjac root powder and was able to test it over the last weekend and found it brilliant!
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With so much positivity about konjac I would like to ask the cost implications too as some markets are pretty sensitive about it.
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Is there a US supplier of this?
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Must update you on this one. After 2 weeks on stability testing all samples (room and elevated temperature) significantly lost original viscosity. Result was water-thin liquid. No good.
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@galina Thank you so much for this feedback, I was planning to incorporate it in few products to replace carbomer and other thickeners, you made my work easy. But I would still try it in other products just for a comparison.
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I’m a big fan of sclerotium gum, goes great with low pH formulations, better skin absorption than xanthan gum in many formulas.
I’ve used konjac too, created a more granular gel, whereas sclerotium and xanthan gums create more of a slimy texture if that makes sense.
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Thanks Galina for the update. I am waiting for a delivery of konjac from Thailand. I’ll test it in sulphate-free shampoo and report back.
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Well, I experienced the same in similar formulation, but it held well in a full cream formulation.
Perhaps it should be combined with another such as guar gum. I have not reached a full conclusion as to why there was a separation, it could be because of the preservative or some other ingredient, it may take a long time to find out, but the fact remains that initially it created a beautiful gel. -
Still waiting on my first Konjac delivery to experiment with but have done some food science reading in the meantime:
“An extreme synergy between Xanthan and Konjac Mannan takes place at an optimal ratio of 80:20 konjac to xanthan, respectively with viscosity build-up as high as 161,000 cP at a 1% total gum concentration.”“A
combination of xanthan gum with konjac can form a gel at any pH
although xanthan alone does not form a gel. At a pH of 5, the two
gums show the greatest synergistic effect with a ratio of 2:3, konjac
has a gelling ability very similar to carob gum but much more
pronounced. Konjac is synergistic with Kappa-carrageenan to form
strong water gels at very low dosages.”(http://www.cybercolloids.net/information/technical-articles/introduction-konjac-properties)
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“On the other hand, konjac glucomannan also gel when mixed with xanthan. Dea et al. 38 ) have indicated that xanthan-konjac glucomannan gels are stronger than those of the equivalent galactomannan systems. Brownsey et al. 20 ) have studied the interaction using X-ray fiber diffraction and suggested that gelation occurred only if the solutions were mixed at a temperature above the xanthan orderdisorder transition temperature. Williams et al. 21 ) have also suggested that the konjac glucomannan interacted with disordered xanthan chains.”
(http://www.tandfonline.com/doi/pdf/10.1271/bbb.56.1188)
“At low NaCl concentration, and low polymer concentration, the xanthan helix order-disorder transition occurs at temperatures T(m) below 90 degrees C. At temperatures above T(m) the rheological observables reveal the onset of network formation involving xanthan chains released from the ordered helical structure. When these systems are cooled back below T(m), extensive network formation develops with large increases in viscosity and in the storage and loss moduli.”
(http://www.ncbi.nlm.nih.gov/pubmed/12099818)
From what my non-chemistry trained mind can gather - a 1% mixture (0.8% konjac, 0.2% xanthan) mixed at a temperature above 90 degrees C should form a stable gel once cooled. Has anyone tried processing it this way?
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I have not tried mixing it that way, but it is an interesting article, which I skimmed, but did not read thoroughly … yet.
I recall from my experiements with it that Konjac will gel with Xanthan or Hydroxyethylcellulose, but forms an inconsistent glob with Sclerotium Gum.Give it as shot. The gist of the article would seem to indicate that you are correct in mixing the two above 90C and it forms a stable gel upon cooling. -
I made a gel using 1% Konjac Root Powder using room temperature distilled water. I noticed that the gel is unstable as it liquefy in 48 hours at room temperature. I must try adding xanthan gum and heating it to 90C. The only problem is when I apply this gel on the skin, it rolls/rubs off the skin. How do I fixed this? Should I use less and use other thickeners? I want to make a thick gel that includes Konjac Root Powder.
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Just wondering if the Konjac issue was solved. I bought some Konjac powder (INCI Amorphophallus Konjac Root Extract) from aromantic.co.uk a few months ago. I had problems formulating a lotion until I re-read their instructions. Once I added 2% (or more) glycerin during the heated phase, it came together & gelled nicely. Is anyone else using Konjac anymore?
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Ancient topic.
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