Home › Cosmetic Science Talk › Formulating › pH stability of zinc oxide as skin protector.
Tagged: emulsion, ph, skin-protector, stability, zinc oxide
-
pH stability of zinc oxide as skin protector.
Posted by Abdullah on June 12, 2022 at 12:35 amCan 1% zinc oxide function as skin protector when used at 1% @ pH 4-5 in emulsion?
Abdullah replied 2 years, 3 months ago 5 Members · 7 Replies -
7 Replies
-
What phase are you adding the zinc oxide to- water or oil? below pH 6 zinc oxide will start dissolving and you will have Zn ions in solution or new complexes which causes some formulation instability
-
evchem2 said:What phase are you adding the zinc oxide to- water or oil? below pH 6 zinc oxide will start dissolving and you will have Zn ions in solution or new complexes which causes some formulation instability
Off topic….as I am looking at Zn options (deo) ….. would this same aspect be true with Zinc Citrate? (Emulsified cream… with pH of 4.4.)
-
I am not sure at this input (1%), but zinc oxide self regulates to pH of around 7 (in SPF or balms products)
I guess you get a slight skin protective benefits as it covers the skin a bit, but I would not rely on it.
-
evchem2 said:What phase are you adding the zinc oxide to- water or oil? below pH 6 zinc oxide will start dissolving and you will have Zn ions in solution or new complexes which causes some formulation instability
I can use it in both phases. I just wanted that skin protection effect of it.
-
Paprik said:I am not sure at this input (1%), but zinc oxide self regulates to pH of around 7 (in SPF or balms products)
I guess you get a slight skin protective benefits as it covers the skin a bit, but I would not rely on it.
Yes for SPF it should be around pH 7. But does it need to be at pH 7 for skin protection too?
-
It has to be higher than 7 and a couple of buffers are needed.But why not just buy a bottle of calamine lotion?
Log in to reply.