@ketchito Thanks for your suggestion. Also I noticed some black particles inside today. So as you suggested previously mostly this might be because this is not preserved. So I decided to repeat this once by adding preservative and an acid to reduce …
Thanks a lot for your response. I used only water and GHPTC (0.4%) and there are no other ingredients. I'm just trying to check how stable this solution is over a period of time before adding surfactants. I want to ensure to use only stable solution…