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Questions about Urea.
Hi,
I have a few questions about Urea.
1) Is it hard to “stabilize”?
- Does it degrade or precipitate? Under what conditions?
- Does it always change the pH of a product? Are there ingredients to add to prevent pH shifts?2) Is there any difference at all between the various forms of Urea: Hydroxyethl, Imidazolidinyl, Diazolidinyl, and Urea USP?
- Is one form more stable/easier to work with than others?
- Do ALL forms of Urea release formaldehyde?Thanks for your time.
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7 Replies
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1) Is it hard to “stabilize”?
Yes
- Does it degrade or precipitate? Under what conditions?
It degrades. Water and temperature presence are enough.
- Does it always change the pH of a product? Are there ingredients to add to prevent pH shifts?
Yes. You need to add a buffer system2) Is there any difference at all between the various forms of Urea: Hydroxyethl, Imidazolidinyl, Diazolidinyl, and Urea USP?
Not every compound with “urea” in the name is urea! Check the molecule to understand.
- Is one form more stable/easier to work with than others?
Urea is only one.
- Do ALL forms of Urea release formaldehyde?
Probably -
@em88 thanks for your valuable information .
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em88 said:- Does it degrade or precipitate? Under what conditions?
It degrades. Water and temperature presence are enough.that’s a new one on me - amides like urea are usually stable unless you have a lot of alkali presentjust out of interest, what does it degrade to?- Do ALL forms of Urea release formaldehyde?
Probablyonly urea/formaldehyde condensates, e.g. imidazolyl urea, do this -
Bill_Toge said:that’s a new one on me - amides like urea are usually stable unless you have a lot of alkali present
There are many articles that mention a degradation of urea in NH3 and CO2.
I’ve noticed myself an increasement of pH over time.
In creams is even easier to spot the bubbles of CO2.
https://www.ncbi.nlm.nih.gov/pubmed/25043489
Indeed, taking in consideration that there are covalent bonds, urea should be stable, but in my experience urea was not stable.Bill_Toge said:only urea/formaldehyde condensates, e.g. imidazolyl urea, do thisMy mistake, was thinking about something else.
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Thank you, @Bill_Toge.
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Hi,
I have a question regarding the stability of my shampoo. I have already checked all the other topics regarding my question, but couldn’t find the right answer, so I’m posting it here.
I’m formulating shampoo for my client. We have Coco glucoside, sodium cocoyl glutamate and CAPB as surfactants, then we have a few moisturizers (B5, propylene glycol). And an additional of 1% urea.
I have lowered the pH to 5.5 with citric acid (use around 0,8%). After a few months (3+) pH is still the same.
My question: Is it necessary to stabilize the urea with a buffer solution regarding the use of a really low dosage of urea (1%). Should I expect to have problems regarding urea decay later (let’s say after 1 year).
Any suggestion /experience in this field is welcome, thank you in advance for your help.
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Please create a separate thread instead of hijacking others question. Because: it is the rule of the forum and more people will see it.
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