Home Cosmetic Science Talk Formulating Solubility of caprylhydroxamic acid in phenoxyethanol or glycerin

  • Solubility of caprylhydroxamic acid in phenoxyethanol or glycerin

    Posted by Abdullah on January 19, 2022 at 2:48 am

    This preservative Phenostat composition is 

    Phenoxyethanol  70%
    Caprylhydroxamic acid  15%
    methylpropanediol  8%
    Water  7%

    My question are

    1. Is this methylpropanediol and water necessary to solubilize caprylhydroxamic acid in phenoxyethanol? 

    2. How much caprylhydroxamic acid can be solubilized in phenoxyethanol and be stored for later use? 

    Bluebird replied 9 months ago 3 Members · 4 Replies
  • 4 Replies
  • Graillotion

    Member
    January 19, 2022 at 3:02 am

    Don’t know the answer to your question…but just gonna toss this out there.  Someone in the know…. once whispered in my ear, that said acid is very incompatible with zinc.

    Just a heads up when formulating with it.

  • Abdullah

    Member
    January 19, 2022 at 5:36 am

    Don’t know the answer to your question…but just gonna toss this out there.  Someone in the know…. once whispered in my ear, that said acid is very incompatible with zinc.

    Just a heads up when formulating with it.

    Thanks ????

  • Bluebird

    Member
    January 14, 2024 at 6:55 am

    This mix may clash with this (rather annoying) Inolex patent. Because of the use of CHA and methylpropanediol in percentages covered in Claim 1.

    “1. A preservative composition blend comprising about 4.5% to about 15% caprylohydroxamic acid or a salt thereof, wherein caprylohydroxamic acid is the only hydroxamic acid in the composition blend, and about 7% to about 95.5% of a diol selected from the group consisting of a propanediol, methylpropanediol, a butylene glycol, 1,2-pentanediol, 1,2-hexanediol, caprylyl glycol, 1,2-decanediol, caprylyl glyceryl ether, ethylhexylglycerin, glyceryl monolaurate, glyceryl monocaprate, glyceryl monocaprylate, and combinations thereof.”

    https://patents.google.com/patent/US10897899B2/en

    • Bluebird

      Member
      January 14, 2024 at 7:26 am

      There’s also this patent, which is even more broad than the one I shared before.

      US/8993641/B2

      It looks to me that any use of CHA with diol in the US without using Inolex’ product is blocked but I am hoping I’m wrong.

      Did you find a clever way to go around this?

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