Home Cosmetic Science Talk Formulating Advanced Questions Preservative issue in cream

  • Preservative issue in cream

    Posted by DavidW on April 11, 2023 at 7:41 am

    Hi all, sorry for the long post I have a cream I have been making for years and it just came to light that there is a growth problem that had been going on for what I assume is a long time but just discovered. bulk product before filling of Initial micro testing of total plate, yeast & mold, pseudomonas comes back good but a few months to a year later it seems to fail big time. The customer complained of the product turning from white to off white so I thought maybe the fragrance. We tested 6 different lots of retains ranging from mfg dates of 07/2021 to 01/2023 (still white and nice). All appeared off white but no obvious growth. Twice in the past we had complaints of brown spots and recalled those. Not sure what is causing it. I am thinking of switching the preservative to either Euxyl PE 9010 at 1% or maybe Neolone PE which is (Methylisothiazolinone (and) Phenoxyethanol) at 0.57%. I haven’t done testing yet to find out exactly what the growth is. Here is the current formulation. Would appreciate any opinions.

    Water 77.58%

    Liquid Germall Plus 0.7% (used to be 0.5%)

    Carbopol Ultrez 21 0.1%

    Propylene Glycol 3.0%

    GMS-SE 2.0%

    Caprylic/capric Triglyceride 2.0%

    Soybean Oil 1.5%

    Cetearyl alcohol (and) Ceteareth 20 2.0%

    Polawax NF 0.5%

    Cetyl Stearyl Alcohol 4.0%

    Liquid Hydrozyled Collagen 1.0%

    Matrixyl 3000 2.0%

    Vitamin E oil 0.3%

    Vitamin A Oil 0.01%

    Hyaluronic Acid powder 0.01%

    Argireline (peptide for wrinkles) 0.1%

    Extract Blend in base of propylene glycol 1.0% (used in many other products and never had an issue)

    Fragrance 0.1%

    Triethanolamine 0.1%

    ketchito replied 5 months, 3 weeks ago 8 Members · 20 Replies
  • 20 Replies
  • philgeis

    April 11, 2023 at 8:59 am

    Not MIT - sensitization problems.

    If phenoxy you’ll still need a counterpart to the “+” of Germall +.

    Any more info on your growthj?

    • DavidW

      April 13, 2023 at 7:32 am

      Thanks for the reply Phil. I don’t have any info on the specifics of what is growing. All I know now is that both total plate count and yeast & mold came back too numerous to count. When you say “If phenoxy you’ll still need a counterpart to the “+” of Germall +” Are you saying if I use Euxyl PE9010 which as you know is phenoxyethanol and ethylhexylglycerin, I should add another preservative as well other than Germall Plus? Or another preservative but not Germall Plus?

      • philgeis

        April 13, 2023 at 9:40 am

        In theory with Phenoxy/EHG - you need to address yeast/mold and to a lesser extent Gram +.

        • DavidW

          April 13, 2023 at 1:01 pm

          Thank you Phil. Would you have any suggestions for additions that won’t affect the function of the Carbopol? I don’t have to use the Phenoxy/EHG either, I can use something totally different.

  • graillotion

    April 11, 2023 at 3:35 pm

    I did not see a mention of pH. You can certainly get some mileage out of a decent pH.

    Have you considered subbing pentylene glycol for the propylene (I know …. higher cost). With that longer carbon chain length… it might point things in the right direction.

    If I were having Y/M/F issues…I probably wouldn’t take the approach of adding more LGP… but hitting it from a different angle….adding a different YMF agent.

    Good luck.

    • DavidW

      April 13, 2023 at 7:20 am

      Due to the fact that we have carbopol in there we are limited on the pH level to maintain the viscosity needed.

  • philgeis

    April 13, 2023 at 4:30 pm

    Per Graillotion’s comment- what’s pH?

    • DavidW

      April 14, 2023 at 10:37 am

      pH range 6.1 to 6.8

  • MarkBroussard

    April 13, 2023 at 5:25 pm

    If you switch to Ultrez 30, it will form a gel as low as pH =4.0. So, you don’t have to go up to pH=6.0 as you do with Carbomer. Note the INCI of Ultrez 30 is Carbomer.

    • DavidW

      April 14, 2023 at 10:37 am

      Thanks Mark.

  • Richard

    April 13, 2023 at 7:18 pm

    Just a thought about Germall Plus from my days of using Diazolidinyl Urea. I assume the order you have listed the ingredients in is the order of addition. This would mean water phase is likely to be heated to around at least 70C. I wonder if the Diaz. Urea could be inactivated to some degree by the elevated temperature. So I wonder if it would be better added as part of the cooling process.

    • DavidW

      April 14, 2023 at 10:38 am

      No, it is not the order of addition. We always add at the end of the process at around 115F

  • manstra

    June 11, 2023 at 3:27 pm

    Hello DavidW

    You should refrain from using carbomers and try using 0,15% guar gum/xanthan gum 50/50 that gives stability over range of PH. At this percentage it won’t have a marmalade like filling. Also Euxyl should be backed up with a polyol system such as dermosoft OM (Evonik)that contains caprylyl glycol and methylpropanediol at minimum 2% in your formula. It will provide an extra microbial growth hurdle.

    • DavidW

      June 12, 2023 at 6:51 am

      We use “carbomers”, more specifically Ultrez 21 in several formulations and have been for over 20 years. I can’t change those formulas now.

  • philgeis

    June 11, 2023 at 3:41 pm

    David - to your original post - do you have micro contamination and if so with what bugs?

    You have a decent preservative system (tho EDTA would help). If a micro problem - it’s likely in your manufacturing hygiene, not your formula.

    • This reply was modified 5 months, 3 weeks ago by  PhilGeis.
    • DavidW

      June 12, 2023 at 6:48 am

      @PhilGeis It wasn’t tested for specific bugs. However both total plate count and Yeast & mold came back with very high amounts in several batches. Nothing else we made before, during the same week or after has failed. In fact I don’t remember anything ever failing expect this product. I think it if was our manufacturing hygiene that something else would have failed too

      An example of one lot was:

      TPC 2.3 x10 ^6 CFU/g

      Yeast & Mold 3×10^4 CFU/g

      • This reply was modified 5 months, 3 weeks ago by  DavidW.
  • abdullah

    June 11, 2023 at 7:27 pm

    Looks like your problem is wiith fungi.

    Maybe some IPBC will help.

    @PhilGeis what is your opinion about this?

    • philgeis

      June 12, 2023 at 12:13 am

      Good idea - and David’s Germall Plus includes IPBC. I’m not sure he confirmed contamination and if so what it was. But Germall Plus should generally be ok unless manufacturing issues or formula incompatibility.

  • DavidW

    June 12, 2023 at 8:36 am

    Just to be clear, we are proactively investigation the issue. We have sent out samples of every chemical used in the manufacture of this product for micro testing as well as samples of the jars and caps. We have also sent out freshly made samples of the product for PET (preservative efficacy testing) testing of the original formula plus 4 other variations using different preservatives. We have also halted production of this product until we find answers.

  • ketchito

    June 12, 2023 at 9:49 am

    If your manufacture is at the industrial level, then you should focus on the pipes, joints, everything that a regular sanitization process won’t cover and where there would be a change to biofilm formation.

Log in to reply.