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Help with preservative % for Hyaluronic Acid serum.
I want to start testing 3 different Hyaluronic Acid powders I have to see if there is a difference and which one works the best in a simple HA 1% strength / DI Water formula and preservative of Inci: Dehydroacetic acid & Benzyl alcohol but not sure what amount of preservative to use i was thinking 0.5% but just wanted to check it on here first if that was enough ?
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10 Replies
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Lots of people here are happy to help, but as many will say you still will need to engage in the basic research. It will lead you to a better understanding of the subject matter. That said; try this link.
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Thanks for the link but I already did the basic research of several preservatives and decided this one is best for me. I know the recommend usage range is 0.5-1.15%
so after more research i came to the conclusion of 0.5% is the figure i needed i just wanted to check on here that my conclusion is correct or i should go and do some more research! -
It is not that simple. Selecting a preservative really takes a big picture approach. What is the final pH? Is it a leave-on or rinse-off product. Packaging is a factor as well.
In the end the only way to get a final definitive answer is to get it tested. Bottom line.
Lastly, if you are going to make Cosmetics you are hardly done researching this preservative or preservation as a whole. I read 3 Journals a month from cover to cover and I would estimate 30% of what I read about is preservatives.
To show how big picture your approach needs to be, check out this website. It is run by a distributor so they recommend their products but in the end you can see how many factors affect this process.
To be truly effective in crafting Cosmetics effectively and safely you MUST put in the time to learn and continue to sharpen this knowledge. Preservation is not an area to take lightly.
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As Mark has said, there is far more to preserving your product than just adding a preservative. A strategy is needed:-1. 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 very important.2. Double check against this webpage whether your preservative is truly broad spectrum -http://makingskincare.com/preservatives/ (If your preservative isn’t one of the 27 reviewed on the webpage above check for it here -https://www.facebook.com/groups/makingskincare/permalink/529462787179550/ (If you can’t access this second link do first join the Making Skincare facebook group here -https://www.facebook.com/groups/makingskincare/)NB: Phenonip, germaben and liquid germall plus are well known amongst cosmetic chemists as broad spectrum preservatives.3. Add glycerin and other polyols4. Add 0.2% disodium EDTA into the heated water phase5. 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% IPA8. Use distilled, deionised or purified water, not tap/faucet or mineral water9. If your water isn’t micro checked, 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.html12. We can’t rely on sight, smell to know if our product is contaminated - 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 usually won’t smell bad. 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.
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Just a quick addition. You decided on the lowest concentration of preservative. As Makingskincare also points out there are many issues. In only the best of conditions (low water content, no difficult to preserve ingredients, packaging, etc.) would you go this low. While I know many due to safety concerns like to use a low level, keep in mind that an insufficiently preserved product is actually MORE dangerous to your clients than any chemical ever will be.
If you look at MakingSkincare’s website, she has a pretty good initial review of preservation and preservatives. I only say initial review because as I said preservation is constantly evolving, especially in regard to naturally compliant products and todays expert would be behind tomorrow if he didn’t stay current.
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Thank you for the comments and all the great info. I agree there is a huge amount to take into consideration when preserving a product and if i go further and wish to create one for resale to the public I will employ a real chemist and have all the test done. But for the moment this is only a personal study and i simply want to test the different HA`s i have to see if there is any notable difference between them, the test should take no more than a few months thats why the 0.5% preserve.
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Actually, Preservation is not that terribly complicated once you understand the fundamentals. But, you MUST understand the fundamentals, particularly as it related to the Hurdle Technology approach to cosmetic formulation.
@Carljen, you are better off using Benzyl Alchol/DHA at 0.8% to 1.0%. Read MakingSkincare’s overview of Preservatives on her site, it covers the fundamental quite nicely.What I find more curious is just how is it that you are going to determine the differences between the Hyaluronic Acid powders. Are they of different molecular weights? Or, the same molecular weight from different manufacturers? … Or, both?What “difference” are you seeking to determine? -
Really never said it was hard or complicated, just not something to take lightly or to attempt without some real study. Perry has a webinar coming up this week for anyone looking to get a good overall picture of the topic.
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Thats brilliant Mark thank you.
I have now read MakingSkincare’s overview of Preservatives on her site, its excellent and highly recommend it to anyone starting out. I will now be adding 0.5% sodium benzoate to the formula as recommended.
Mark, I have 2 different weights, one large and small and one with encapsulated multi chain, just want to see if there is a notable difference between them.
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If you are using Super Low Molecular Weight, it will not thicken your formulation. Anything higher than SLMW will thicken your formulation. If you are making an aqueous-based serum, you will notice the difference. If it’s a lotion, cream, gel-cream … you will not notice any difference between SLMW and higher molecular weight HA.
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