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Lactic acid in deodorant… Need help to understand
hello, if you please would help me about this.
I formulated deodorant as following:Cetostearyl alcohol 5 %
Viscolam AT 100p 2% emulsifier
(inci;Sodium Polyacryloyldimethyl Taurate, Hydrogenated Polydecene, Trideceth-10)
Carrageenan 0.2 %
Oils 6%
Sorbitol 2%
Edta 0.1
Zinc oxide 5%
Zinc ricinoleate 3%
Kaolin 5%
Corn starch 2%
Licorice extract 5%
Aloe vera extract 1%
Vit.E 0.5 %
Preservative 0. 5%
Fragrance 1%
Water up to 100The consistency of the cream is good and it’s spreading over skin.
But, I found the ph about 9. I used lactic acid to lower it.
I added 3% lactic acid, ph now 7.1
I still need to lower it to 5.5 but idk if high percent of lactic acid would be irritant for the underarm ? Do i need to add sodium lactate with it?
And is the kaolin & zinc oxide causing that high ph? -
16 Replies
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Licorice extract 5% - that is a huge amount. What kind of extract is that?
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@Belassi
It is a water based extract -
the zinc oxide is reacting with the acid, which is why you’re needing to use a lot of it - I’d suggest removing the zinc oxide
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@Bill_Toge
Zinc oxide is active ingredient for its antimicrobial effect and reducing odor.
If i use citric acid to lower ph, is it still react with zinc oxide? -
Amira said:@Bill_Toge
Zinc oxide is active ingredient for its antimicrobial effect and reducing odor.
If i use citric acid to lower ph, is it still react with zinc oxide?zinc ricinoleate (already in the formula) will do that job a lot betterwith zinc oxide, the same thing will happen with any acid -
@Bill_Toge
Thank you. I will try the formula without zinc oxide. That’s supposed to lower ph. -
Belassi said:Licorice extract 5% - that is a huge amount. What kind of extract is that?
It is 70 % water extract as I told by the supplier
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The thing is, licorice is not very soluble. The pure acid is about 0.2% soluble. I buy a powdered root extract, direct from China. It is a yellow-brown powder with 12% of the licorice acid active ingredient and reasonably soluble because it also contains saponins. Frankly, any liquid licorice extract you buy is likely to contain a risible amount. I use 0.2% of the 12% powder in shampoo, and it is plenty.
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@Belassi
Now, i am willing to remove zinc oxide, lower licorice extract may be to 2%.
But as a thought, if i used niacinamide (for underarm depigmentation along with the licorice extract) and i used lactic acid to adjust ph to 5.5
Would it be right? -
You won’t see any skin lightening effect with that kind of licorice extract, at least I don’t think so.
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Belassi said:You won’t see any skin lightening effect with that kind of licorice extract, at least I don’t think so.
Would you please expalin to me why?
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Because we have already tried it, with far higher (twenty-fold) concentrations than what you are using. And it didn’t work.
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@Belassi
Ok, thank you for this.
But, what would you recommend for lightening effect (no for vit c, kojic for oxidation & high ph problems) -
We had good results using organic shea butter in a hand cream (noticeable after about three weeks use) presumably due to the vitamin A precursors. But that is no good for your application. You could try potassium glycyrrhizate (the soluble salt of the pure acid) - I make that sometimes by reacting the pure acid (from China of course) with potassium hydroxide. But, it is a salt and can be destabilised by various things including certain preservatives (eg dehydroacetic acid).
I agree about vitamin C, even the very expensive palmitate, Aprecier, oxidised in an airless container despite my best efforts and endless reading of patents. -
@Belassi
Unfortunately, Potassium glycyrrhizate is not available here nor the acid. I would leave the idea of lightening effect for now.
Thank you so much for your input and the information. -
I know, it’s hard to get hold of. I bought mine from China via mail order. Everyone here in the post service seems to think it’s just fine for people to be ordering kilograms of white powder from China!
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