Home Cosmetic Science Talk Formulating Heat Stable Preservatives?

  • Heat Stable Preservatives?

    Posted by julianrebecca on July 10, 2024 at 8:19 pm

    Hello, can I please have some help determining alternative preservatives if possible?

    I appreciate your expertise and any advice would be great.

    I make a balm that is:

    37% glycerin

    11% emulsifying waxes,

    4% surfactant

    47.5% water phase

    this heats to above 100 degrees Celsius and becomes a thick balm,

    when it cools to 80 degrees Celsius, i add 0.5% Optiphen Plus.

    By this time the balm is very thick and I am concerned the preservative may not disperse through all the water phase and I am wondering whether there is a preservative or material i can add when the mix is still liquid at around 100 degrees celsius?

    Thank you all. I appreciate any insight or advice.

    PhilGeis replied 5 months ago 4 Members · 19 Replies
  • 19 Replies
  • chemist-chef

    Member
    July 10, 2024 at 10:09 pm

    Hi,

    I think you can try Iscaguard OPP (INCI : Propylene glycol, O-Phenylphenol)

    “Iscaguard OPP is a liquid preservative containing O-Phenolphenol. This preservative has a wide spectrum of activity, and can tolerate high pH environments ranging from 3.0-14.0, and also high processing temperature of 200°C.”

    Since it has very low solubility in water, you can try to dissolve this preservative in surfactant, after that you can introduce it with your water phase.

    • PhilGeis

      Member
      July 11, 2024 at 5:08 am
      • chemist-chef

        Member
        July 19, 2024 at 1:58 am

        Hi, thank you for the insight about O-Phenylphenol.

        But I just check the Annex V,List of Preservatives Allowed in Cosmetic Products, O-Phenylphenol is still in the allowed preservative for cosmetic products.

        <div>It is stated : The use of o-phenylphenol as a preservative should be allowed with a
        maximum concentration of 0,15 % (as phenol) in leave-on and 0,2 % (as
        phenol) in rinse-off cosmetic products.

        Contact with eyes should be avoided.</div>

        May be it’s not recommended for cleansing balm or any kind of products that may contact with eyes, but it’s still allowed as cosmetic preservative.

        Thank you for the insight.

        • This reply was modified 5 months, 1 week ago by  chemist-chef.
        • PhilGeis

          Member
          July 19, 2024 at 10:40 am

          The list hasn’t been touched for decades but for alerts from activists - Parabens - and the contact derm folks - MIT. There is and has been virtually no use of OPP to for anyone to notice. Even the activists are not so stupid as to sensationalize something no one uses and the derm folks deal with reality.

          The stuff is not only classified as a carcinogen, it is an irritant.

    • julianrebecca

      Member
      July 11, 2024 at 5:30 am

      Hello, I appreciate your suggestion.

      I have searched for the material and admittedly, I have never used it before!

      What are the best applications or ways you have used the material?

      I like to learn new things, so I am interested to hear your experiences with it.

      • PhilGeis

        Member
        July 11, 2024 at 7:45 am

        I’ve used it in disinfectants - consumers complained about skin irriation. Never used it as a cosmetic preservative.

    • julianrebecca

      Member
      July 11, 2024 at 8:24 am

      Hello, I appreciate your suggestion.

      I have searched for the material and admittedly, I have never used it before!

      What are the best applications or ways you have used the material?

      I like to learn new things, so I am interested to hear your experiences with it.

  • PhilGeis

    Member
    July 11, 2024 at 5:13 am

    You do have dilemma - addition to finshed product will certainly risk poor distribution and 100C is a bear for chemical and physical stability.

    Do you consider this a water in oil or oil in water?

    • julianrebecca

      Member
      July 11, 2024 at 5:23 am

      Hello, I appreciate your advice and willingness to understand.

      I would consider it a water in oil.

      The reaction that takes place is what causes the materials to thicken into a balm, its quite novel.

      But when i test the temperature after the reaction, it has reached above 100C so i wonder whether the temperature is also a factor or the catalyst to the reaction?

      • PhilGeis

        Member
        July 11, 2024 at 8:01 am

        Not sure you need a preservative. If really 100C, you’ll certainly eliminate process contamination. Is it hot fill? and what is package? Water in oil - are intrinsically less susceptible. Challenge testing is not suitable - it’ll prob fail preservative or no. You wonder where the glycerol is - if in water phase, it’ll have an effect. Where does it come in process?

        Right - you’ll never get preservative in post process.

        The real test would be in use.

        • julianrebecca

          Member
          July 11, 2024 at 8:21 am

          Thank you. Yes hot fill. Jar pot/lid packaging.

          I’ve been experimenting with the ratios while using the product. It performs well. It surpassed expectations.

          Your right, as it is now I don’t expect it would pass PET. But since speaking with you, I am considering experimenting with the method, to determine whether the temperature is the catalyst or the byproduct.

          Should I use naticide perhaps? As it’s water soluble at 0.6% and heat stable upto 80C.

          Optiphen Plus is oil/glycol soluble which isn’t the portion of the formula I’m worried about so maybe I should switch?


          • PhilGeis

            Member
            July 11, 2024 at 8:56 am

            Good grief - forget Natacide and other mystery preservatives. Phenoxy is prob not great - flashing off at 100C, partitoning is not favorable with w-in-o and Gram negs are prob not your biggest risk. Please talk about the chemical not the commericial name.

            Challenge - fail not because it’s unpreserved but because the challenge droplets with bacteria/fungi never effectively merge with water in your water-in-oil emulsions. The same phenomenon governs contamination in use. Unlesss exposed to water in use - your risk is fungal contamination under high humidity so phenoxy is not that useful. If direct exposure to water - preservative in water droplets in w-in-o prob won’t see the bugs and any preservatibe will not be effectively available. Bugs from skin don’t come woth enough water to grow.

            • This reply was modified 5 months, 2 weeks ago by  PhilGeis.
            • julianrebecca

              Member
              July 11, 2024 at 9:05 am

              I like the aroma of naticide and yes your right it is a mystery chemical.

              Wow I am learning alot from you, I didn’t know challenge testing is, bacteria/fungi on a water droplet, so what your saying is the balm is too thick to be challenge tested because the water droplet won’t migrate wow that’s interesting.

              Perhaps I reduce the water content to make it inherently self preserving but that brings me back to the other great points you made. Fungi from humidity exposure, what if I change the packaging to an airless jar or tubes? Would that negate the risk?

            • PhilGeis

              Member
              July 11, 2024 at 9:29 am

              Hot filled tubes are certainly at very limited risk.

              Why not make/package product and let your freinds screw around with it, encourage them to use and often in any way they wish - get it back and check for bugs.

            • julianrebecca

              Member
              July 11, 2024 at 4:55 pm

              Thanks so much for sharing your thoughts and expertise. I think I will go with tubes 👍

              I was predominantly a quality manager and various other roles (inventory management, R&D, purchasing) for four large cosmetic manufacturers spanning ten years, (prior to this I studied cosmetic chemist and quietly nurtured my passion) subsequently I have higher standards than the average person so I don’t give my products to family to try because in the past when I did that, their opinion was too biased. All I got back was good feedback.

              Im thinking as I move forward. I will create samples and give to target customers for feedback.

              Thank you 🙏 I really appreciate your suggestions.

  • megi

    Member
    July 12, 2024 at 10:23 am

    Hi,I have a question unrelated to our previous discussion. I’m looking for help in creating a 3D capsule cream similar to this one. It appears to be a two-phase product, consisting of jelly and lotion, which can be mixed together. However, I’m not sure how to create it, especially for a large batch. Could you please assist me with this? Thank you.

    • PhilGeis

      Member
      July 12, 2024 at 10:59 am

      You should post as a primary question.

    • julianrebecca

      Member
      July 15, 2024 at 10:44 pm

      Hi Megi,

      It appears to be a gel serum with the capsules suspended in it. Have you tried the product? Do the capsules dissolve on application? I haven’t used those before.

      I have used Unispheres (NT range) - Which are tiny beads that are composed of Mannitol, Cellulose and Hydroxypropyl Methylcellulose. Each material in the NT range incapsulates different raw materials, For example NT 2403 encapsulates retinyl palmitate for example, others a tocopherol, others hyaluronic acid etc and they dissolve as you rub them in.

      We made a basic water based gel serum using Sepimax Zen (Polyacrylate Crosspolymer-6) as the thickener. Adding the unispheres at the end.

  • megi

    Member
    July 16, 2024 at 12:39 am

    Hi. Thank you for the explanation. Yes, I have used it. They dissolve perfectly together. They are like moisturizer beads suspended in gel. I haven’t tried to formulate yet. I don’t know how stable it will be, especially for shipping, and creating the beads in large quantities. I’m planning to try using a syringe as a filler for them. But I need to clarify how to formulate the beads. They are so smooth, and feel like moisturizer when you touch them.<div>

    That’s the inci they have in package:Water/Aqua/Eau, Hippophae Rhamnoides Water, Glycerin, Caprylic/Capric Triglyceride, Dipropylene Glycol, Niacinamide, 1,2-Hexanediol, Butyrospermum Parkii (Shea) Butter, Squalane, Glyceryl Glucoside, Panthenol, Dimethicone, Tromethamine, Carbomer, Propanediol, Polyglyceryl-10 Laurate, Polyglyceryl-2 Stearate, Arachidyl Alcohol, Ammonium Acryloyl-dimethyltaurate/VP Copolymer, Stearyl Alcohol, Glyceryl Stearate, Parfum/Fragrance, Behenyl Alcohol, Ethylhexylglycerin, Cetyl Alcohol, Arachidyl Glucoside, C12-16 Alcohols, Adenosine, Caprylic/Capric Glycerides, Hydrogenated Lecithin, Palmitic Acid, Xanthan Gum, Myristyl Alcohol, Amylodextrin, Maltodextrin, Calcium Pantothenate, Lauryl Alcohol, Sodium Ascorbyl Phosphate, Tripropylene Glycol, Pyridoxine HCl, Tocopheryl Acetate, Propylene Glycol, Tocopherol, CI 16035 (Red 40), CI 19140 (Yellow 5)

    </div>

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