Studies that Compare Preservatives

Tagged: formulating, preservative, preservatives, safety

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Studies that Compare Preservatives

Posted by natzam44 on January 14, 2021 at 2:49 pm

Hello,

I was wondering if anyone knew of a study that compared a large number of preservatives? I feel as if I have seen one before but can’t seem to find it and it is driving me crazy.

Thanks,
Nathaniel

Pharma replied 3 years, 10 months ago 4 Members · 9 Replies
9 Replies

Pharma

Member
January 14, 2021 at 7:42 pm

Most publications I’ve come across were either old, used just the 4-5 most common lab microbes, included irrelevant preservatives, used irrelevant/ridiculous formulations, or were sponsored by cosmetic industry (usually the producer of the ‘winning horse’).

Besides that, such studies are quite often utterly useless in practical everyday life unless you use exactly the one formulation of the publication.

Maybe focus more on the different spectra (gram+, gram-, yeast, fungi) and modes of action (if known) of single preservatives. Also take into account if they are pH dependent, inactivated by certain ingredients, volatile (headspace preservation), interfere with emulsions, act as ‘…static’, ‘…cide’, or booster, logP and surfactancy, species of current contamination, and so on… These things alone may not suffice but can give you a good head start when choosing a new or tweaking a current preservative system.
natzam44

Member
January 15, 2021 at 3:52 am

@Pharma I’m mostly interested out of sheer curiosity rather than wanting to use the study for practical use but thanks for the information nonetheless.
Graillotion

Member
January 15, 2021 at 7:26 am

@Pharma, just for fun….if you were tasked by some big cosmetic company to formulate a general purpose emulsion preservative system, using three readily available components….what would it be? And let’s throw on the constraints of no parabens and no formaldehyde. Knowing you…you will want more details… but this is more an exercise in….One size fits all (which it doesn’t). Ok…you twisted my arm… pH range of 4.8-6.0

And this question is open to all! Let’s have some fun formulating the next great preservative. Any commentary on your thought process…will be a vital learning experience for me and other readers.
PhilGeis

Member
January 15, 2021 at 3:23 pm

Add rinse off (esp. surfactant based) or leave on emuslion.
natzam44

Member
January 15, 2021 at 4:59 pm

@Pharma What a ridiculous question.

All I need is salt, water, and citric acid. Just mix salt and water in a 1:2 ratio and then adjust the pH to 2. No problem.
natzam44

Member
January 15, 2021 at 5:00 pm

natzam44 said:

@Pharma What a ridiculous question.

All I need is salt, water, and citric acid. Just mix salt and water in a 1:2 ratio and then adjust the pH to 2. No problem.

Just realized I went outside of the pH range. Woopsie.
Graillotion

Member
January 16, 2021 at 4:00 am

PhilGeis said:

Add rinse off (esp. surfactant based) or leave on emuslion.

Leave on emulsions….of course!
natzam44

Member
January 16, 2021 at 6:21 am

@Graillotion I just realized that I tagged Pharm instead of you in my above comments. Sorry!
Pharma

Member
January 16, 2021 at 6:27 am

Hmmm… Do antioxidants, chelates, and boosters also count as part of the preservative system or are we talking traditional preservatives?

As an imaginary employee of ACME (A Cosmetic Multibillion Enterprise), I would propose benzisothiazolinone. Maybe add some other stuff such as chlorphenesin, just to be on the safe side .

Me as me, I wouldn’t touch that stuff, just to be clear!