Home Cosmetic Science Talk Formulating Multiple preservatives in a system

  • Pharma

    June 29, 2020 at 5:37 pm
    Depends… usually, one uses blends in order to not just broaden the spectrum but also to be able to use lower amounts for the single constituents.
    A preservative (or a blend thereof) should be used at the minimal required amount, not the maximum. Do some microbial contamination testing to figure out how much your product actually requires.
  • Abdullah

    June 30, 2020 at 7:15 am

    @yes blends are better but my question was is there any rule to not use two preservative to there maximum when we blend them? 

    For example: in Euxyl®
    k700 which is: Phenoxyethanol 30%, benzyl alcohol 30%, potassium sorbate 15%, tocopherol 15%, 
    water 15%. The maximum allowed is %1.5, that becomes %0.45 benzyl alcohol and %0.45 phenoxyethanol. 

  • OldPerry

    June 30, 2020 at 12:50 pm

    Preservative regulations are set based on the total amount in a formula. It doesn’t matter if you add the preservative by itself or if it comes in a blend. If you get 0.45% phenoxyethanol from the blend, you could still add 0.55% more phenoxyethanol by itself. 

  • Abdullah

    July 6, 2020 at 12:19 am

    @Perry thanks

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