Prevent green discoloration of cream with salicylic acid

You apparently set two questions.

The first question about the discoloration should most likely be linked to salicylic acid, a product that easily discolours under the influence of metals, which may well prevent it from being in minimal quantities. Thus, best Na2EDTA can be added in a concentration of 0.1%.  

Or salicylic acid is incompatible with chlorhexidinedigluconate, I cannot exclude it with certainty. I do know that salicylic acid is incompatible with PEG-containing compounds like cetomacrogol. So is a cream based on Laurylsulaat a better choice but in this recipe we come from the drop   in the rain there we then get to deal with the incompatibility Chlorhexid + with lauryl sulfate. There is the possibility that the lauryl sulfate present does not react all the way so that sufficient O/W emulsifier remains for the formation of the emulsion.   This is not the case then NaCl (+/-30 mg) can be added, so that the digluconnat converts to the insoluble dihydrochloride is an option to neutralize the pernicious effect of chlorhexidine. Chlorhexidine Dihydrochloride is a salt that is used in antiseptic creams.  

We can therefore recommend: 1. Add EDTA and check that the discoloration is left out; 2. Add NaCl and use a cream based on lauryl sulfate like e.g. Beeler basis.