stearic acid and pH of emulsion

ShamsShams Member
Hi everyone

Seeking advice. If I am using stearic acid in a lotion formula (with other emulsifiers not alone) do I have to have the pH above 7 to ensure that it is doing it's job as an emulsifier . Or can I still adjust my lotion to around 5.8 pH?
Any good sources to read more on stearic acid woul;d be highly appreciated. I have been looking for a while but couldn't find any.
Thanks in advance


  • singhc10singhc10 Member
    @Shams For In Situ emulsion with stearic acid, you would need to to go between pH 6.5-7.5 for complete saponification, Saponification is irreversible reaction, so you could re adjust the pH with Citric acid of your emulsion. Still advise to look at the stability
  • chemicalmattchemicalmatt Member, Professional Chemist
    I would suggest otherwise: saponify with tromethamine (the best now that TEA is out) to pH 6.2 - 6.8, leaving some free acid, both as builder and to prevent pearlescence on aging.
  • ShamsShams Member
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