Home Cosmetic Science Talk Formulating Surfactant Oxidation with sorbates and benzoates

  • Surfactant Oxidation with sorbates and benzoates

    Posted by Mich on November 1, 2019 at 2:10 pm

    Does anyone observed oxidation or stability issues when combining Sodium cocoyl glutamate, Sodium Lauroamphoacetate (surfactant base) with Potassium sorbate and sodium Benzoate preservative syst. for hand soap application.  After a week in accelerated stability the solution turns clear yellow and and 2nd to 3rd week turns clear orange, and develops a sweet aroma.  
    I suspected the potassium sorbate had an effect on this reaction but i starting to believe that could be the other way around.  The sorbate moiety has two double bonds prone to oxidation. 
    Thanks

    Vnnil replied 4 years, 6 months ago 4 Members · 4 Replies
  • 4 Replies
  • EVchem

    Member
    November 1, 2019 at 3:07 pm

    Are you adjusting pH in this? those surfactants have a higher pH, and your preservative system is useless above pH 5.5-6. If you do go that low your surfactants might have issues though

  • Mich

    Member
    November 1, 2019 at 5:26 pm

    pH 5 to 5.5

  • Bill_Toge

    Member
    November 1, 2019 at 8:41 pm

    this is a well-known ‘feature’ of sorbate salts in water-based products; they’re best suited to dry/hygroscopic products

  • Vnnil

    Member
    November 7, 2019 at 4:03 pm

    Adding citric acid/sodium citrate helps with sorbic acid oxidation 

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