Home Cosmetic Science Talk Formulating Microbiological growth in rinse off products.

  • Microbiological growth in rinse off products.

    Posted by MurtazaHakim on October 13, 2021 at 2:26 pm

    Greetings to forum members.

    My query is related to the microbiological growth in rinse off products. What could be the possible sources for the contamination of the product with the following bacteria.
    1. Pseudomonas Stutzeri
    2. Aeromonas Salmonicida
    3. Non-fermenter spp.

    What are the solutions to prevent such microbiological growth in any rinse off products such as hand soap ?

     

    Abdullah replied 2 years, 8 months ago 8 Members · 29 Replies
  • 29 Replies
  • ariepfadli

    Member
    October 13, 2021 at 2:57 pm

    Try with formaldehyde releaser such DMDM Hydantoin,  imidazolidinyl urea, etc. They effective and safe for rinse off products

  • PhilGeis

    Member
    October 14, 2021 at 2:08 am

    Try with formaldehyde releaser such DMDM Hydantoin,  imidazolidinyl urea, etc. They effective and safe for rinse off products

    Good ones above but recommend as best Na benzoate/chloromethyl isothiazolinone /EDTA.
    However these are manufacturing contaminants - appears you need major improvement in manufacturing hygiene and GMP’s.  Preservatives are largely intended to protect during consumer use.

  • ozgirl

    Member
    October 14, 2021 at 2:33 am

    I would check your raw materials to ensure that they are not the source of contamination.

  • EVchem

    Member
    October 14, 2021 at 2:47 pm

    All good points so far- What preservative are you currently using and what is your water source?

  • MurtazaHakim

    Member
    October 14, 2021 at 5:33 pm

    @ozgirl the raw materials are surfactants like sodium laureth sulfate, cocamidopropyl betaine and linear alkylbenzene sulfonic acid; rheology modifiers like sodium chloride, fragrances, colorants.

    @EVchem currently I am using tap water and Proxel 106 as a preservative.

    Is water the primary bacterial source ???
    Is a robust preservation system not sufficient to prevent microbiological growth ??? 

  • ariepfadli

    Member
    October 14, 2021 at 5:54 pm

    Proxel 106 already robust preservation, are you used based on recomendation? 0.1-0.3% (1-3 ml/ kg product)?

  • Bill_Toge

    Member
    October 14, 2021 at 5:57 pm

    tap water is not sterile - depending where it’s sourced from, and the ambient temperature, it can be crawling with microbes

  • EVchem

    Member
    October 14, 2021 at 6:14 pm

    definitely agree with bill- tap water introduces huge potential burden, you can test it to confirm but ultimately for consistency you should get DI water at least

  • MurtazaHakim

    Member
    October 14, 2021 at 6:20 pm

    Which microbiological tests are recommended for the tap water which I am using ???

    I have come across total plate count test but there may be other more reliable and accurate tests. Please provide your valuable insight on this issue. 

  • Macrophage

    Member
    October 14, 2021 at 7:30 pm

    Ditch the tap water. 

  • MurtazaHakim

    Member
    October 15, 2021 at 8:56 pm

    Is proxel 106 a suitable preservative to be used for hand soaps ??? 

  • Abdullah

    Member
    October 16, 2021 at 2:46 am

    What is the composition

  • PhilGeis

    Member
    October 16, 2021 at 10:02 am

    Is proxel 106 a suitable preservative to be used for hand soaps ??? 

    No.    It’s formaldehyde with CMIT/MIT.  The formaldehyde is not needed - as it shares efficacy with CMIT.  It’s intended for paints coatings etc. where manufacturing contamination is typically pretty bad and the two strong preservatives help against resistance development..  Think some folks consider formaldehyde presence in head space in can discourages mold.

  • MurtazaHakim

    Member
    October 16, 2021 at 10:34 am

    What are the recommended preservatives then especially for rinse off products ???

  • PhilGeis

    Member
    October 16, 2021 at 10:48 am

    Suggest CMIT/ Na benzoate /EDTA unless you formulate to be politically-correct.  Good luck with that.

  • MurtazaHakim

    Member
    October 16, 2021 at 11:21 am

    Is Biocrol WS1 from CISME Italy a good option for preservative ???

  • PhilGeis

    Member
    October 16, 2021 at 2:19 pm

    it’s CMIT - keep it less than 5 ppm active and combine with Nabenzoate and EDTA

  • MurtazaHakim

    Member
    October 16, 2021 at 3:24 pm

    Why is there a need to combine CMIT with sodium benzoate and EDTA ???

    Is Biocrol WS1 alone at the dosage of 0.15% w/v not sufficient to inhibit microbiological growth in rinse off products ??? 

  • PhilGeis

    Member
    October 16, 2021 at 4:15 pm

    Na benzoate broadens the spectrum and EDTA complexes divalent cations, esp. Ca++ to destabilize biofilm/capsule..  CMIT is primarily effective vs Gram negative - Na benzoate in surfactant context increases efficacy and broadens spectrum.  Two preservatives should make it  ore difficult for the microbes to adapt.

  • MurtazaHakim

    Member
    October 17, 2021 at 6:32 am

    Sodium benzoate’s activity is very low at pH above 5 and liquid hand soaps usually have pH ranging from 5.5-7.5.

  • MurtazaHakim

    Member
    October 17, 2021 at 9:59 am

    Is Lonzaserve ID a better option for rinse off products ???

  • PhilGeis

    Member
    October 17, 2021 at 10:39 am

    Sodium benzoate’s activity is very low at pH above 5 and liquid hand soaps usually have pH ranging from 5.5-7.5.

    Re. Na benzoate, In presence of  some surfactants, the pKa is effectively increased.  I’ve found effect at 7 .   Please look at labels - CMIT/Na Benzoate is in Head & Shoulders, Pantene, Herbal essences, Aussie - all pH well above pKa.

    Lonzaserve ID is a combination of DMDM Hydantoin and CMIT - very effective but prob overkill as they share the same primary spectrum of efficacy tho discouraging adaptation.  might be advisable if you’ve a resistant bug in your manufacturing system.

  • MurtazaHakim

    Member
    October 17, 2021 at 11:16 am

    What would be better to use Biocrol WS1 or Lonzaserve ID ???

  • PhilGeis

    Member
    October 17, 2021 at 4:58 pm

    With the contamination you mentioned, probably the latter with EDTA.  Your primary fix must be in bringing GMP’s, manufacturing hygiene and possible biofilm into control..

  • MurtazaHakim

    Member
    October 17, 2021 at 5:04 pm

    What form of EDTA should be used ??? Is it tetrasodium EDTA solution ???

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