Home › Cosmetic Science Talk › Formulating › General › Better humectant: urea or sodium lactate
-
Better humectant: urea or sodium lactate
Posted by DaveStone on October 31, 2021 at 9:19 amWhich do you prefer?
vitalys replied 2 years, 10 months ago 6 Members · 8 Replies -
8 Replies
-
They work in different ways.
Why choose.
I use them both in the same product.
-
Graillotion said:They work in different ways.
Why choose.
I use them both in the same product.
How do they work differently? Which is molecularly smaller?
-
Not so sure about humectancy and those two, since urea is generally used as a keratolytic. Place a 40% urea solution on your nail plate and overnight the nail will have dissolved and you’ll be ready for toe surgery. Reason for using sodium lactate-lactic acid with high urea content is that is the best buffering system to stabilize urea at pH 5.0 - 5.5. Urea decomposes (reduces) into ammonia in aqueous solution - just ask any farmer who uses it for fertilizer.
-
chemicalmatt said:Not so sure about humectancy and those two, since urea is generally used as a keratolytic. Place a 40% urea solution on your nail plate and overnight the nail will have dissolved and you’ll be ready for toe surgery. Reason for using sodium lactate-lactic acid with high urea content is that is the best buffering system to stabilize urea at pH 5.0 - 5.5. Urea decomposes (reduces) into ammonia in aqueous solution - just ask any farmer who uses it for fertilizer.Urea can dissolve healthy nail too? Or just fungal-infected nail?Isn’t sodium lactate keratolytic as well over 10%?
-
40% Urea is one of the strongest keratolytics, as @chemicalmatt mentioned, but at the concentration of 5-7% it becomes one of the most powerful humectants ( I would say the best one).
@DaveStone Yes, 40% Urea will dissolve a healthy nail too. -
I use sodium lactate on its own but I never use urea (in o/w) without sodium lactate (because buffer). As per my anecdotal experience nothing saves dry hands quicker than urea + sodium lactate.
-
@Perry Actually, they are comparable in their effect, but still different. These two substances can apparently complement each other in different preparations. It also depends on a formulation and its purpose. However, there are plenty of formulations where Urea shows more pronounced and prolonged effect. For example, the special formulations for hand and foot care. I completely agree with @ngarayeva001 that urea is the best component to improve dry skin conditions. I can say the same about feet, atopic skin conditions, severe ichthyosis, hyperkeratosis, etc
Log in to reply.