Home Cosmetic Science Talk Formulating Ramping down Spectrastat by Inolex to 0.4%

  • Ramping down Spectrastat by Inolex to 0.4%

    Posted by Bluebird on June 5, 2023 at 7:41 am

    Hi,

    So Inolex recommends 0.8% upward for its Spectrastat preservative mix (CHA, caprylyl glycol, glycerol) in the U.S.

    However I learned from a Korean distributer that in this country, many cosmetics producers have used 0.4% and they are recommending 0.4%.

    I would be curious to hear from anyone who has indeed ramped down Spectrastat to 0.4% and has an idea about its efficacy, preferably has done the challenge test.

    My formulation is water type.

    Bluebird replied 1 year, 1 month ago 4 Members · 17 Replies
  • 17 Replies
  • Graillotion

    Member
    June 5, 2023 at 3:07 pm

    The answer will always be…. depends on the rest of the system. Fill it with tons of hurdles and hexanediol, should be no sweat. Forget about hurdles and fill it with bug food….Not a chance. 🙂

    <content edited per request>

    • Bluebird

      Member
      June 5, 2023 at 8:12 pm

      Is your brilliant friend one of your alter egos?

      In any case, this is a lot of gem to read.

      First, I had read about hydroxamine concern, not in the CIR report (that’s good to know it’s also there), but some Australian gov report. But there, I only read “purported concern” at low and high pH, nothing concrete. So I had asked the Inolex about this and asked whether at pH 4, there is concern of hydroxamine formation and whether they had tested. The answer was that it’s stable at broad pH and for use at pH 4-8 (but they didn’t specifically said it was tested).

      I wonder where your friend found the rat study-if available, I’d like to read.

      The Korean Inolex distributer told me that 0.4% has been used and tested by many Korean cosmetics producers and there’s enough data to know that it works in general. No mention of any further need of preservatives such as hexandiols. Korea is strong in cosmetics, it’s a serious industry, I do think they do have some information to say that-otherwise, it will potentially get into a legal trouble. But it is a distributer, not the developer, and also you are mentioning many things that are important to consider, if true, and clearly your “friend” is very knowledgeable and has thought a lot of this, so this makes me thinking again as well.

      But what safer, effective, and also importantly, consumer-friendly (meaning, even if paraben were not bad, I wouldn’t use it if my consumers don’t like it) alternatives would you have in mind as a preservative for a low pH water based system?

      I tried citric acid to adjust pH (that’s to help lower skin bacterial load), used mix of (caprylyl glycol + 1,2 hexandiol) at 0.5% (this is another ready-made mix by a cosmetics company that I used; they didn’t reveal exact ratio, but says final 0.5% will work) for anti-bacterial effect, and potassium sorbate 0.15% for anti-mold/yeast effect.

      I haven’t yet done the challenge test of that yet, just read the potassium sorbate concentration for leave-on products and tried that for my prototype.

      The “problem” I observed: damn it, a new smell arises!

      I believe citric acid reacts with potassium sorbate, leading to the formation of sorbic acid, which has a distinct smell.

      I could smell it from my formulation, my family members couldn’t, so I’m not sure how “bad” or “unpleasant” or “noticeable” this smell is at this concentration, but for my nose, I do smell this acidic kind of note that, if all things equal, I prefer not to have in the product. However, it seems it’s weak enough that a little bit of perfume would solve.

      I could try using lactic acid, but that would also lead to a bit of sorbic acid I imagine, plus the smell of the lactic acid itself.

      I read about sodium benzoate too, but read that citric acid+benzoate+vitC can lead to the creation of benzene. As someone who sometimes tries megadosing vitC, I really don’t fancy developing a formulation w/ sodium benzoate for this reason.

      So what do we have left here? 🙁

      I have a pretty strong Gram-positive antibacterial already in my formulation.

      And I think capryly glycol alone or w/ 1,2 hexandiol would be fine for Gram negative bacteria.

      I need something against mold and yeast.

      Specifically, I need something that is against mold and yeast and preferably not have strong anti-bacterial effect, if at all.

    • Bluebird

      Member
      June 8, 2023 at 2:57 am

      An update: got actual data from Inolex, stability of CHA at pH4: stable, with no detection of hydroxamine via mass spec.

      • PhilGeis

        Member
        June 8, 2023 at 5:28 am

        Is this for a probiotic?

        • Bluebird

          Member
          June 8, 2023 at 8:54 am

          Are you being sarcastic?

          It’s a preservative

  • Graillotion

    Member
    June 5, 2023 at 6:40 pm

    BTW….isn’t ‘ramping down’ the formula for creating super bugs? ????

    I would have to imagine…Inolex did some basic testing to come up with their recommendations. If they wanted to sell more product…they could have just increased the filler ingredient, and upped the use rate.

    As I recall…some preservatives actually become ‘bug food’ if you get the rates too low. Not saying in regards to this one….but applies to some.

    • Bluebird

      Member
      June 5, 2023 at 8:17 pm

      Yeah, ramping down could be a problem, BUT it could be that the level included by the US Inolex is just too high. I wouldn’t be even thinking about ramping down to 0.4% if the Korean branch didn’t actively recommend it.

      You are right that many ingredients are food for bacteria.

      Sugar, for instance.

      And in Spectrastat, glycerol!

      • Graillotion

        Member
        June 5, 2023 at 9:06 pm

        Did they provide any supporting material along with this recommendation? (I mean other than cost savings.)

        • Bluebird

          Member
          June 5, 2023 at 9:17 pm

          No, they also don’t say “you can save cost by cutting it to half and it still works fine.”

          In Korea, it seems manufacturers just know it as 0.4%. Isn’t that a bit surprising. But from what I’ve seen, cosmetics regulation is more stringent in general in Korea than in the US. So what I mean, based on this, I have a reason to think that it may actually work?! But I’m still surprised. And no, I haven’t seen data, but know that if there were no data, these other people who do use 0.4% wouldn’t have passed the test by the gov. ☹

  • Abdullah

    Member
    June 5, 2023 at 9:35 pm

    caprylyl glycol + 1,2 hexandiol is 50:50.

    What is your pH?

    • Bluebird

      Member
      June 5, 2023 at 9:37 pm

      Okay, pH is 4 to 4.5, aqueous solution. Any problem?

      • Abdullah

        Member
        June 5, 2023 at 9:44 pm

        What ingredients are in your product and what is your product?

        This preservative doesn’t work well in surfactant systems.

        I would not use less than 1% in any case.

  • Abdullah

    Member
    June 5, 2023 at 9:45 pm

    Your caprylyl glycol + 1,2 hexandiol and potassium sorbate will be a better option at that pH.

    • Bluebird

      Member
      June 5, 2023 at 10:18 pm

      Okay. Are you saying that based on concern for hydroxamine as well?

      • Abdullah

        Member
        June 5, 2023 at 10:39 pm

        No

        I say that because at pH 4 potassium sorbate is better option than CHA in anyway and caprylyl glycol + 1,2 hexandiol is better than caprylyl glycol alone.

        0.15% potassium sorbate at pH 4 is more powerful than 0.06% CHA

        0.15% potassium sorbate is less expensive than 0.06% CHA

  • PhilGeis

    Member
    June 6, 2023 at 6:32 am

    Makes to difference - it’s a poor preservative system at an y concentration.

    • Bluebird

      Member
      June 8, 2023 at 8:55 am

      Why do you say so?

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