Sodium salicylate for yeast and mold

Can sodium salicylate at pH 5 cover yeast and mold in emulsion and shampoo? 
If yes, at what percentage

Comments

  • PharmaPharma Member, Pharmacist
    pH 5 is limit and you'd need quite a bit. Salicylic acid works best below pH ~4. You might get away with it in blends. However, I lack any experience/knowledge in that regard.
  • PhilGeisPhilGeis Member, Professional formulator
    No - it can not.  
  • PhilGeisPhilGeis Member, Professional formulator
    btw - mold contamination oif shampoo is a very, very rare observatiuon.
  • AbdullahAbdullah Member
    @Pharma thanks 
    @PhilGeis which microbes grow in Shampoo most?

    The ingredients are surfactants, polyquaternium 10, essential oil, NACL, and Amodimethicone in near future. 
  • PhilGeisPhilGeis Member, Professional formulator
    Abdullah said:
    @Pharma thanks 
    @PhilGeis which microbes grow in Shampoo most?

    The ingredients are surfactants, polyquaternium 10, essential oil, NACL, and Amodimethicone in near future. 
    Pseudomonads (esp. Burkholderia cepacia and P. aeruginosa), less so enterics.  Fungi esp. mycelial fungi should not be expected.
  • PharmaPharma Member, Pharmacist
    @PhilGeis Good to know! P. aeruginosa is a really nasty bug especially in the shower with all the aerosol and the main reason why many eye drops have to be used within 1 month after opening! Although 'only' an opportunistic human pathogen, for those who do get an infection... Ouch!
  • AbdullahAbdullah Member
    @PhilGeis that is good information to know. I will increase the amount of EDTA from %0.1 to %0.2 then. My preservatives are %0.1 caprylhydroxamic acid and %1 Glyceryl Caprylate in Shampoo.

    Can you give some information on which one of these pathogens grow more in which type of products or environments?

    - Staphylococcus aureus
    - e coli
    - Candida albicans
    - Aspergillus niger

  • PhilGeisPhilGeis Member, Professional formulator
    edited April 2
    Not wild about your system. The hydroxamic acid is largely going to impact fungi, that and the glyc cap are pretty weak sisters vs the bad guys mentioned below.  Do you have a "policy" that controls what you can use (e.g. no formaldehye releasers)? 

    Only Staph aureus and Candida albicans are pathogens, and none grows very well in cosmetics products.  They're just in the classic preservative test test.

    As pharma said, you need to watch out for Pseudomonas aeruginosa as well as  Burkholderia cepacia and other Gram negatives. 
  • PhilGeisPhilGeis Member, Professional formulator
    I'll tell you why I think it's weak
    Capryl hydroxamate is an iron chelator  - (like ZPT - another hydroxamate)- competes with hydroxamic acid siderophores such as those fungi use to solubilize/transport iron.   You already have EDTA as chelator and Pseudomonas aeruginosa et al.  are not bothered by such compounds.
    Glyceryl caprylate is really a crap preservative.  It's an ester that Pseudomonad esterases eat for lunch.

  • AbdullahAbdullah Member
    edited April 3
    @PhilGeis interesting
    this is a patented preservative blend by Inolex. Spectrastat™ G2 Natural MB
    Caprylhydroxamic acid  %0.1
    Glyceryl Caprylate  %0.75
    Glycerin   %0.15

    Why would they spend time and money patenting what is not effective enough? 

    I also use Ethyl Lauroyl Arginate HCl in with glyceryl caprylate in some lotions. What is your opinion about that?

    What preservative blend do you suggest? (no formaldehye releasers, parabens and mi/cmi)

  • PharmaPharma Member, Pharmacist
    PhilGeis said:
    ...
    Capryl hydroxamate is an iron chelator  - (like ZPT - another hydroxamate)- competes with hydroxamic acid siderophores such as those fungi use to solubilize/transport iron...
    Not just that, it also complexes zinc and copper very well. The trick isn't just about making micronutrients unavailable for microbes but complexing these metals within enzymes to render the whole machinery useless. At least, that's the hypothesis. It's also a medium chain fatty acid derivative and many of these have a certain inherent antimicrobial potential. However, having worked with hydroxamic acid derivatives, I'm highly sceptical and fairly concerned about their safety.
  • PhilGeisPhilGeis Member, Professional formulator
    Abdullah said:
    @PhilGeis interesting
    this is a patented preservative blend by Inolex. Spectrastat™ G2 Natural MB
    Caprylhydroxamic acid  %0.1
    Glyceryl Caprylate  %0.75
    Glycerin   %0.15

    Why would they spend time and money patenting what is not effective enough? 

    I also use Ethyl Lauroyl Arginate HCl in with glyceryl caprylate in some lotions. What is your opinion about that?

    What preservative blend do you suggest? (no formaldehye releasers, parabens and mi/cmi)

    Why?  To exploit the alternative/"natural" preservative market.  Prob about as useful as most of the systems marketed in that category. 

    I've not used Ethyl lauroyl arginate - maybe pharma has some relevant experience.   It's a food preservative - seen some caution that it's more active in vitro than in use - and used in some mouthwash products for plaque and for "antimicrobial" packaging" so prob substantive.  Read functionally, it's a cationic surfactant -  maybe not so great with anionics in shampoos.

    For shampoos and with your policy constraints - will you use benzyl alcohol or  phenoxyethanol?  Perhaps with benzoate and EDTA.
  • AbdullahAbdullah Member
    @PhilGeis thanks. I have used in the past these blends. Benzyl alcohol and DHA @%1.1, sb and ps @%1.6.
    In blind test i can say almost every time which one has one of these two preservatives and which one has Glyceryl Caprylate and CHA. The last one feels better.
    benzyl alcohol and phenoxyethanol are acceptable if there is no milder alternative in reasonable price range and in amounts no more than %0.5. the rest should be milder preservatives.

    I have used Ethyl Lauroyl Arginate HCl in Shampoo. It had the best feeling. Maybe because of its conditioning effect. But it is not compatible with chelating agents EDTA and sodium phytate and it is expensive too. so i am not using it in Shampoo anymore.

    There is a blend called SymOcide PH which is claimed to be broad spectrum.
    Phenoxyethanol  %0.6
    Hydroxyacetophenone  %0.25
    Caprylyl Glycol  %0.1
    Water %0.05

    So would adding %0.2 or %0.3 hydroxyacetophenone make this blend strong enough?

    Glyceryl Caprylate %1
    Hydroxyacetophenone %0.2 or 0.3
    CHA  %0.1
    EDTA or sodium phytate %0.1


  • AbdullahAbdullah Member
    Pharma said:
    PhilGeis said:
    ...
    Capryl hydroxamate is an iron chelator  - (like ZPT - another hydroxamate)- competes with hydroxamic acid siderophores such as those fungi use to solubilize/transport iron...
    Not just that, it also complexes zinc and copper very well. The trick isn't just about making micronutrients unavailable for microbes but complexing these metals within enzymes to render the whole machinery useless. At least, that's the hypothesis. It's also a medium chain fatty acid derivative and many of these have a certain inherent antimicrobial potential. However, having worked with hydroxamic acid derivatives, I'm highly sceptical and fairly concerned about their safety.
    Thanks. 
    So you mean CHA is a strong preservative when used in blends?
  • PharmaPharma Member, Pharmacist
    As said, I'm highly sceptical and fairly concerned ;) .
    I couldn't find any scientific data regarding its antimicrobial potential. There seems to be virtually no publicly available data regarding its preservative action.
    Overall, there is very little literature regarding CHA... However, it does seem to penetrate skin. For me, reasons enough not to use it (besides the fact that hydroxamates have, for a long time, been considered 'don't touch, don't even think about it' by pharma companies). Only recently, SAHA and the like became popular but they affect, simply explained, how genes are read. Doesn't seem very healthy if you're not fighting a disease with it.
  • AbdullahAbdullah Member
    @Pharma thanks
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