Preservative quantity suggestion for 0.5% allantoin+0.25% tetrasodium EDTA solution
I am making a simple solution of 0.5% allantoin + 0.25% tetrasodium EDTA in water.
pH adjusted to 5-5.5 with citric acid.
Packaging is in 220ml flip top cap.
What amount of phenoxyethanol+ caprylhydroxamic acid do you recommend as preservative for this solution?