Home Cosmetic Science Talk Formulating Preservatives for polysorbats

  • Preservatives for polysorbats

    Posted by mehran31 on April 26, 2014 at 2:02 am

    Dear colleagues

    Polysorbats offset the effect of common preservatives and I am looking for a preservative which can work in polysorbat surfactant solution. 
    thanks for your help
    ozgirl replied 9 years, 11 months ago 6 Members · 13 Replies
  • 13 Replies
  • MakingSkincare

    Member
    April 27, 2014 at 11:45 am

    Liquid germall plus

  • mehran31

    Member
    April 27, 2014 at 4:00 pm

    Thanks dear but as I studied Germall plus description and have found it should not be used in aerosol products. I am going to formulate an aerosol product then I can not use it.

  • OldPerry

    Member
    April 28, 2014 at 7:52 am

    It would help if you could give us an idea of the ingredients in the formula & what the formula is used for.

  • mehran31

    Member
    April 30, 2014 at 3:41 am

    Dear Perry

    I am going to formulate air fresheners.
    They have a simple structure: essential oil (3%), ethanol ( 4%) anti bad odor (forestal) and solubilizers (polysorbats).
  • OldPerry

    Member
    April 30, 2014 at 10:27 am

    For an aerosol product with a significant amount of alcohol, why do you need an additional preservative?

  • Chemist77

    Member
    April 30, 2014 at 10:33 am

    @Perry I think if the formula is without water then you are right but if he forgot to mention water here then 4% ethanol ain’t sufficient. Or what is the carrier for the formula?

  • Bobzchemist

    Member
    April 30, 2014 at 11:46 am

    The easy answer is to just use enough preservatives so that you overwhelm the polysorbates ability to inactivate them.

  • OldPerry

    Member
    April 30, 2014 at 2:41 pm

    @milliachemist - good point.  The concentrate will have to be preserved.  But if the product passes a challenge test prior to filling in the aerosol, I would think it wouldn’t need a preservative when put under pressure as this would be an air-tight environment.

  • mehran31

    Member
    April 30, 2014 at 6:24 pm

    Dear colleagues

    I forgot to say air freshener are water base and I have to balance it to 100 percent by water.
  • ozgirl

    Member
    April 30, 2014 at 10:11 pm

    Have you considered methylisothiazolinone or benzisothiazolinone or a quaternary preservative like benzalkonium chloride?

  • mehran31

    Member
    May 1, 2014 at 2:49 am

    Yes, polysorbates offset the effect of these preservatives.

  • Bobzchemist

    Member
    May 1, 2014 at 9:57 am

    @mehran31 - Polysorbates are not alive - they do not gobble up one molecule of preservative and move on to the next. They also do not otherwise inactivate all of the preservatives that could ever be put into your formula. 1 molecule of polysorbate inactivates exactly 1 molecule of preservative, then stops. 

    So, the industry strategy has usually been to overwhelm the inactivation capacity of the polysorbates with a higher level of preservatives than would ordinarily be used without the presence of polysorbates in the formulation. This higher level must be confirmed sufficient by running a PET/challenge test.
    Yes, this is an expensive way to do things. Preservatives usually cost much more than polysorbates, so many chemists have tried to find other solubilizers to use that do not inactivate preservatives.
  • ozgirl

    Member
    May 1, 2014 at 6:37 pm

    Perhaps the easier thing to do would be to find a different solubilizer. Maybe you should ask your supplier of the polysorbates what they would recommend.

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