-
Itching After using a lotion
Hello! my name is Vanessa, am a biochemist who has taken interest in becoming a cosmetic chemist. I recently made a lotion containing the following ingredients:
•Rose H2O,
•aloe juice,
•Stearic acid,
•glycerin,
•xanthum gum
•sepiwhite,
•L ascorbic,
•E wax,
• co enzyme Q10,
•T resveratrol,
• allatoin,
•EDTA,
• phenoxyethanol
with synthetic fragrance.I gave 7 of my friends to try it out but 1 people is complaining of itchiness after using the product. Which of these ingredients can cause that. Thank you.
-
15 Replies
-
One person? Pretty much any of those ingredients.
But most likely phenoxyethanol, resverstrol, allantoin, rose water, aloe or fragrance. Or maybe your pH is too low.
-
Ok noted. Thank you so much. My final PH was 4.5
-
Hi Perry,
Thanks for the feedback; so I am thinking of replacing rose water and aloe with just plain distilled water, replace phenoxyethanol , take out Allantoin and resveratrol and use essential oils as fragrance.
Also increase pH to 5. What do you think?
-
It’s also concentration/dose-dependent. People can help you better if you write down the % too. I use phenoxyethanol and allantoin all the time, but I have never experienced itchiness.
I would rather omit the L-AA, it’s very unstable and a potential irritant.
And ethereal (‘essential’) oils can be just as irritable as synthetic perfume oils, sometimes even more so.
Also, your emulsion is very weak on fungi and yeast, with only phenoxy present.pH 4.5 is on the low side, probably because of the L-AA.
-
How are you getting the stearic acid to combine with water? The formula does not appear to be complete. L-Resveratrol is almost insoluble.
-
@Belassi I used t resveratrol (It is liquid) and added at the end of formulation. I add the Stearic acid to the oil phrase
-
This formed my oil phrase
-
@vanne The T-resveratrol you use in your whitening lotion is from making-cosmetics.com? I presume? in which case it also contains PEG-7 Glyceryl Cocoate and Propylene glycol (not that either of those should be particularly irritating).
The “emulsifying wax” you use, could you specify which? (some of them contain SLS which can be irritating if left on the skin, even though the concentration is low some people are more susceptible.
Regarding the ascorbic acid, you would be better off removing it or substituting with a stabilized version (Magnesium Ascorbyl Phosphate for example) as ascorbic acid is extremely unstable and will auto-oxidize into dehydroascorbic acid (with a yucky brown/orange color).
The percentages used of the potential irritants mentioned would be beneficial to assist.
-
@Sibech
Regarding ascorbic acid. I have experienced orange discoloration due to Maillard reaction, ascorbic acid as reducing sugar -> amino acids in skin. I had orange staining of hands and bed sheets and the smell was typical of that of a cheap self tanner. It was a very concentrated (≥20%) L-AA serum. (The serum itself had no smell and no colour btw)Now what still isn’t clear to me, and I hope you or anyone else can answer: does the Maillard reaction with L-AA trigger oxidation reactions?
Maybe it’s just psychological, but the discoloration + awful smell didn’t feel like it was stimulating collagen synthesis at all. :joy:
(p.s. I gave up topical L-AA a long time ago)
@vanne
Ok, maybe it’s best to list all the ingredients + percentage.
But… neem oil? Yikes! -
@doreen When dissolved in water (no stabilizers) the oxidation occurs relatively slowly but after a month or two on the shelf (I had satd. L-AA) then it was suddenly orange/brownish.
Are you sure it wasn’t spray-tan in serum form? (Because dehydroascorbic acid (DHAA) was at least considered for use as a sunless tanner (patent) due to the reductive capacity of DHAA.
-
Come to think of it, there is a chance that the discoloration of the saturated solution was due to complexing with metal ions in the water (it was for pH correction in cooking, not cosmetics).
-
@Sibech
No, there wasn’t a self tanner involved. @johnb has helped me with this and concluded that a Maillard reaction has taken place, with L-AA as reducing sugar. I’ve searched several sites/forums and I see more women complaining about their vitamin C serum (only with L-AA, not a stable ester), whether it’s an expensive brand or home made. The same complaints: the staining, the smell. @johnb explained that in these cases it was possible due to the high dose of L-AA (to have the Maillard taken place without heat, or only body warmth).So it might not be such a good (temporarily) whitening ingredient after all. :joy:
p.s. You’re right! DHAA as self tanner. I remember! Some brand tried to have it patented.
But doesn’t that mean that in the case of the vitamin C serums triggering Maillard reactions, that somehow there is DHAA present, one way or the other?Hey… I haven’t seen this link before. I don’t know if this is right, but it looks interesting:
https://labmuffin.com/vitamin-c-can-stain-skin-avoid/
@vanne
I’m sorry for hijacking your post! I’ll quit here and start a new thread if I have more![misc] Every Vitamin C Serum that I use tends to smell like wet dog on my skin... Is this an issue for anyone else?
byu/AtrophicSPIN inSkincareAddiction -
(only with L-AA, not a stable ester)
Even using a very expensive form of Vitamin C, (Aprecier) I was unable to get beyond a 10-week shelf life.
Log in to reply.