Hello, I am currently developing a gel cream formula that contains
1.Carbopol Ultraz 21
3.Active includes Alpha Arbutin , Tranexamic Acid , B3 , vit c (GO VC)
The problem encountered is that after storing for a while, the cream changed from white to light brown. and has a sour smell
So I tried preparing it again by adding Active Protec ™ OX 1% to the water part.
Found that the cream was more liquid. It can be made into a lotion. and thickens when in a room with a high temperature
But the cream color has not changed in any way.
I don't know what needs to be changed. Or are there other anti-discoloration and odor prevention agents that would be suitable for this gel-cream formula? Are there any recommendations?