Home Cosmetic Science Talk Formulating Airless bottle packaging – preservating?

  • Airless bottle packaging – preservating?

    Posted by Anonymous on August 25, 2014 at 3:59 am

    Hi there,

    We store our products in airless bottles for the costumers. We use dermosoft 1388 ECO to help keep the products preserved. The products include extracts, ferments, aloe.

    What do you guys think of this?

    We have never experiensed any germs, bacteria after a few months use.

    MakingSkincare replied 9 years, 10 months ago 4 Members · 8 Replies
  • 8 Replies
  • The_Microbiologist

    August 25, 2014 at 11:52 am

    He ELDEskin,

    Well, you asked :)

    I think you’re playing with fire.  Here’s why:  Many common preservatives are incompatible with certain other formula ingredients, and it’s often surprising which combinations “knock out” the preservative activity.  Without testing, you’ll never know whether or not that is happening in your formulation.

    Also, typical micro QA is not sufficient to indicate a product is well preserved because micro QA is typically done right after production, before bacteria and fungi have a chance to get a toehold and begin reproducing.  It is also possible that your production to date has been unusually hygienic or that by luck it hasn’t introduced too broad a range of microorganisms (each one bringing its own set of tools to feed on the product).

    I think you should run a simple challenge test on the formulation (preferably at a good, specialized microbiology lab).  Challenge tests like USP 51 use a broad array of microorganisms introduced to the sample in great numbers.  95% of the time, they’ll pick out formulations that are not biologically stable.  To pick out bad formulations 100% of the time, manufacturers make them even more challenging with repeat inoculations, an additional set of microbes, diluting the product before the test, etc.

    If you do not run a challenge test there is a risk - and we don’t know how great - that the product will support microbial growth.  That will result in spoiled product at a minimum and health risks as a worst case outcome.

    One last thought - most microorganisms of concern in cosmetics grow fairly well in anaerobic (air free) environments, so the airless packaging helps to control contamination but can’t be counted on to prevent it entirely.

    Good luck!


  • Anonymous

    August 27, 2014 at 8:11 am

    I understand what you are saying.

    What about a combination of dermosoft 1388 ECO, Glyceryl Caprylate (Dermosoft GMCY) and p-Anisic Acid (Dermosoft 688)? This would be a natural alternative.

    We have also seen that a lot of organic products use Benzyl Alcohol, Dehydroacetic Acid, Gluconolactone, Sodium Benzoate which is eco-certified, but not as natural?

  • OldPerry

    August 27, 2014 at 8:49 am

    “…not as natural”?

    What do you mean by this?
  • Anonymous

    August 27, 2014 at 9:37 am

    It is not derived from nature, but petrochemicals. So, it’s syntethic. I know “natural” is a term that changes from person to person.

  • Bobzchemist

    August 27, 2014 at 10:57 am


    It’s been said (over and over) that it is impossible to tell if a preservative or preservative system will be adequate by looking at potential ingredients on paper.
    If you gave us the entire formula, with percentages, an experienced chemist could make an educated guess about the likely success or failure of your preservative system. BUT…there are so many variables, including the cleanliness of your manufacturing system, the micro burden in your raw materials, etc. that the ONLY way to tell for sure is to run the challenge test.
    Also - without a challenge test results on file, it is possible that a FDA audit could determine that your company has not adequately proven the safety of your product. This could have a number of consequences, all of them bad, but some are extremely bad.
  • Anonymous

    August 27, 2014 at 2:55 pm

    @Bobzchemist We will take the products on a run through test, we just want to figure out which kind of preservative is the best for us to use and that is as “natural” as possible.

    The creams:


    Add p-Anisic Acid (Dermosoft 688) to the calculation.

  • Anonymous

    August 27, 2014 at 3:33 pm

    Or what about Dehydroacetic acid & Benzyl alcohol together with dermosoft 1388 ECO, or used alone? It is a component of many essential oils and alcohols, and that fits our “natural” claim.

  • MakingSkincare

    August 28, 2014 at 3:11 am

    1. Have a check of this webpage to check if your preservative has the potential to be broad spectrum -http://makingskincare.com/preservatives/ NB: from the choices available to homecrafters: Phenonip, germaben and liquid germall plus tend to be more effective.
    2. Minimise sources of energy for microbial growth (aka “bug food”) - eg fruit, botanicals, tea, lecithin, mineral water, milk of any kind, honey, hydrosols, floral waters, aloe vera, extracts, protein, clay, powders, starches etc - reduce these to a tiny % (eg 0.1%). This is crucial, especially if you’re using one of the more “natural” type preservatives.
    3. Add glycerin and other polyols
    4. Add 0.2% disodium EDTA into the heated water phase
    5. Switch to packaging which the customer can’t contaminate easily - jars are the worst for contamination. 
    6. Reduce the pH to between 4 and 5 if possible.
    7. Sanitise your equipment with 70% IPA
    8. Use distilled, deionised or purified water, not tap/faucet or mineral water
    9. Heat and hold your water phase at 75c/167f for 20 minutes - this will kill some of the non-endospore forming bacteria. (If your preservative can withstand heat put it in the heated water phase rather than the heated oil phase. This improves preservative contact with the water phase so that it is not partitioned in the water-oil interface).
    10. If possible micro test all of your raw materials.
    11. Use good GMP - http://www.mariegale.com/good-manufacturing-practices/gmp-basics.html
    Don’t rely on sight, smell - one can put 100,000 bacteria into a milliliter of water and the water will appear to the naked eye to be crystal clear and won’t smell.  Most cosmetics tested have counts ranging into the tens of thousands or millions of cells per milliliter have subtle or no aesthetic differences from sterile samples. The only way to know if your preservative system is working is to get it tested.

Log in to reply.