Home Cosmetic Science Talk Formulating General Preservative for Ultrez 21 Solution

  • Preservative for Ultrez 21 Solution

    Posted by Zeeshan on May 5, 2020 at 11:15 am

    Hi All,

    I have made an Ultrez 21 solution for our production of hand sanitizer gel.

    As the solution will stay for a while before it’s used, what can I use as a preservative to avoid mold or any microbial activity. We have sodium benzoate and potassium sorbate in stock.

    Thanks.

    Chemist77 replied 4 years, 1 month ago 5 Members · 6 Replies
  • 6 Replies
  • belassi

    Member
    May 5, 2020 at 2:42 pm

    Methyl parabens. Effective at a low %
    The two you mention are useless at neutral pH.

  • OldPerry

    Member
    May 5, 2020 at 3:23 pm

    DMDM Hydantoin works well too. (0.2%)

  • DRBOB@VERDIENT.BIZ

    Member
    May 5, 2020 at 5:53 pm

    phenoxyethanol at 1%

  • Zeeshan

    Member
    May 6, 2020 at 8:56 am

    Belassi said:

    Methyl parabens. Effective at a low %
    The two you mention are useless at neutral pH.

    What % of Methyl Paraben would be effective, as I can source it.

    Also, how do I incorporate it? Can I dissolve in hot water?

    Thanks.

  • belassi

    Member
    May 6, 2020 at 3:07 pm

    Methyl paraben is water soluble. The amount would depend on other factors such as how long you want to preserve it for, the status of the water used, etc., but usually, 0.3% is around the norm.

  • Chemist77

    Member
    May 21, 2020 at 7:43 am
    Actually you could use those ones that you have in stock as the ultrez solution I believe will be non-neutralized and hence pretty acidic. But again once you neutralize the solution to make the sanitizer, the viscosity won’t be as much as it should be as those preservative salts would be detrimental to the viscosity neutralized gel. So in this scenario, I would stick to what Perry and Dr. Bob have mentioned. 

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