Home Cosmetic Science Talk Formulating How much phenoxyethanol do you recommend for this sodium salicylate solution?

  • How much phenoxyethanol do you recommend for this sodium salicylate solution?

    Posted by Abdullah on February 1, 2022 at 2:27 am

    This is a simple solution of sodium salicylate in water. 
    Ingredients are 
    1% salicylic acid
    0.5% aminat G= 0.1% ethyl lauroyl arginate HCl in glycerin (cationic)
    0.29% NaOH
    80 ppm EDTA 

    pH around 5

    I want it to be simple and inexpensive.

    What percentage of phenoxyethanol do you recommend as preservative in this solution

    Abdullah replied 2 years, 4 months ago 3 Members · 6 Replies
  • 6 Replies
  • gordof

    Member
    February 11, 2022 at 8:50 am

    Did you try that already ? can you solubilize all phenoxyethanol in your water phase? normally the biggest part will be on top if you don’t have any Thickeners or emulsifiers present to get it in the system. If you have tried and it works I would say 0,6 -0,7 % should be enough due to the fact that you have salicylic acid which will help with conservation as well as a cationic. 

    I would recommend you to use something like Na-Benzoate K-Sorbate as a conservation system. it is much more available for the water phase and therefore more efficient in that kind of formulation from my experience. 

    0,3 % Na Benzoate 0.2% Kaliumsorbate would do the trick with 1 % salicylic acid I would guess. 

  • PhilGeis

    Member
    February 11, 2022 at 2:20 pm

    What is packaging?
    Aminat G offers something as a multifunctional but think you need something more or Gram negatives.  Phenoxy at 0.5% might work

  • Abdullah

    Member
    February 11, 2022 at 3:17 pm

    @Gordof yes i have tried it. I did use 1% phenoxyethanol and it was completely solubilized.
    As i don’t use any fragrance,  at 1% the smell of phenoxyethanol was a bit annoying so i asked if lower amount can work in this system.

    Benzoate and sorbate is anionic and as i have a cationic present they may not be compatible. Aminat g is fungicide too. 

  • Abdullah

    Member
    February 11, 2022 at 3:20 pm

    @PhilGeis it is 130ml bottle with flip top Cap. 

    I thought about gram negative too. 
    Thanks 

  • PhilGeis

    Member
    February 11, 2022 at 3:35 pm

    That helps a bit - but still try <1% - highest I use is 0.5% and down to 0.3% can be useful.

  • Abdullah

    Member
    February 11, 2022 at 3:58 pm

    PhilGeis said:

    That helps a bit - but still try <1% - highest I use is 0.5% and down to 0.3% can be useful.

    Thanks. I have made sample with 0.5% too and the smell problem was solved compared to 1%. I just wanted an expert to confirm if that amount is ok. 
    Thanks 

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