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antibacterial wipes
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I will try HEC, I have 23 kg bags coming. Thanks. I made a 5% BAC solution (with 1% EDTA 4Na). The pH was somewhere around 10.50. It worked perfectly well with no issues.
My idea was then to manufacture a 0.5% concentration using that initial 5% solution. I noticed it feel out of solution/became cloudy at around the 0.5% concentration. The pH was still high because of the EDTA. I was able to get it back in solution using small amounts of KOH. Alcohol also worked at around 4% w/w. I then created a fresh 0.5% solution with no EDTA and had the same issue of not being soluble in water - measured pH was 7.00.
I don’t really know whether being soluble or not would affect microbial activity. I would assume that it has to have an effect on activity if it is not in solution. It definitely needs to be formulated at an alkaline pH. Maybe pH 7.4 is not enough?
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@Cafe33 just an educated guess, but the enhanced antimicrobial activity from cationic surfactants (over anionics) is their affinity for certain membrane negatively charged compounds. BAC also has a bulky benzene ring that may be playing a role in membrane destabilization.
Because the mechanism of action agains microbes is by denaturing their membranes (physical) and relies on charge, I would believe that the BAC needs to be dissociated to have any effect (or to at least cling to the skin). I was reading somewhere that testing did not show a significant improvement cfu between washing hands with just soap/detergent vs one with BAC immediately after. However, BAC did show a cumulative, longer lasting effect as it stays on the skin. I should probably find that source so you can take a look. But what I’m gathering from this is that if dissociated, it will more effectively stick to the skin due to static charges.
https://www.drugbank.ca/drugs/DB11105 I also found this source, in the pharmacodynamics section it does mention that pH does not seem to affect effectiveness, but contact time does.
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a little late in the discussion…Take a look at this the for BAC https://www.who.int/patientsafety/information_centre/Last_April_versionHH_Guidelines%5B3%5D.pdf?ua=1I mostly agree with the WHO opinion , I’ve seen studies showing that BAC is only acceptable as sanitizing when combined with benzethonium chloride at high levels,it could sensitize skin and there’s a concern of enviromental accumulation and cross-resistance to antibioticsBesides all surfactant base formulations with foaming capabilities and rinse-off are considered “Antibacterial” cause the actions of rubing, foaming and rinsing the product are effective to remove most harmful microbes , and unless you have a very stric and specific regulation to fulfill, with this thinking you can ambiguously claim antibacterial , I don’t belive the addition of BAC or cetrimonium chloride will add an additional antibacterial benefit to the final user considering also the short contact time and that most of the active will be rinsed-offSo maybe you could use Cetrimonium Chloride as a conditioning agent and only a little amout of BAC if it helps with the marketing story of your productFor the marketing story maybe you could also check Chlorhexidine or chloroxylenol for improved compatibility with anionic surfactants ( Since I haven’t work with these ingredients I don’t know their safety profile , aesthetics or regulatory status)
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Thanks letsalcido.
So how does pH affect the dissociation of BAC in water? And if dissociation is associated to it’s microbial properties, this would be an important detail.
HAL49, yes I have considered that in fact regular soap and water with 20 sec rubbing time is antibacterial… so perhaps BAC is only a claim ingredient. Either way, we use the 10 or different formulations I have made at home to wash our hands. It would be great to test these claims.
We will be reaching out to COFEPRIS in a matter of a few weeks, however I heard that their offices were closed during the pandemic. Perhaps, they have re opened. Hell, they just re opened the Casinos here! Yet, the corona virus brigade goes around bothering families at the beaches indicating them to disperse.
We do have a contact for a consultant but I am open to anyone who understands the Mexican landscape of compliance. Not sure if the antibacterial claim is a drug claim in Mexico. I see many companies making acne and anti microbial claims, and some even sold at Sephora here.
PS: What is the technical term “Contact Time” in Spanish? Does it even exist, it is driving me crazy!
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@Cafe33 Yeah BAC as a claim ingredient sounds great!!I don’t know if the COFEPRIS offices are already open , but yeah the situation with coronavirus is ridiculous , here all bars and restaurants are open but a lot of goverment offices and public sport places are closed with lots of security :# , it just does’t make any senseI haven’t deal directly with regulation affairs since my area of expertise is formulation but I do know that the only thing that Mexican regulation says about claims in cosmetic products is:“La información que se presente al consumidor, debe ser veraz y comprobable”So pretty ambigous and permissive , there are not guidelines for claims nor nothing(exept for SPF claims) like regulation in other countriesI don’t know either if there are guideliness for antibacterial claim in the drug regulation , but I’ve seen cosmetics using antibacterial claims using the thinking I mentioned before , recently I saw some big and known brands using “antibacterial” with just an “*” and a tiny disclaimer that says “all soaps are antibacterials” , so they were not using any antibacterial activeI think “Contact Time” is simply “Tiempo de contacto” at least is how i’ve seen in the documentation I’ve checked like http://www.salud.gob.mx/unidades/cdi/documentos/capitulo9.htmlRegarding the pH , BAC is active in the range from 4 to 10 https://www.americanpharmaceuticalreview.com/Featured-Articles/38885-Antimicrobial-Preservatives-Part-Two-Choosing-a-Preservative/so a very good and wide range , it is important however to keep it in solution for it to be active as letsalcido said , it precipitates in your final formula ?the thing that I don’t know is if the pH affect the ability of BAC to cling to the skin , so maybe @letsalcido could shed some light on this topicthe other thing is that it can be inactivated also by nonionic surfactants https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6942038/ , it can still work if you have a high concentration to compensate so just for you to be cautious about it
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@HAL49 @Cafe33 I’m by no means an expert about this topic. I’ve just been doing reading about this because I wanted to make some antibacterial cleaners for my own use, and just putting to use some of that degree that is just hanging on a wall otherwise…
Again, going off of this source https://www.drugbank.ca/drugs/DB11105 pH does not seem to have an effect on activity.My take on all this is that as long as it is dissolved and there is no anionic surfactants in the formulation it should be active. Being most effective in leave on products (no-rinse hand sanitizers, surface cleaners, etc). Lab testing will be the only certain way to determine if the formulation is effective.And I agree “contact time” would be “tiempo de contacto”
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Thank you for the continued discussion. I think I will lower the pH of my hand soap to 6.00-6.50 and then send it out for testing.
HAL49, it most definitely precipitates out of solution when in the 0.5% range. It starts out cloudy and then a smaller layer will settle at the bottom over 24 hours or so. Addition of KOH makes it clear again as well as adding EtOH as solubilizer. I discovered this while formulating a regular disinfectant, not the hand soap.
About the “tiempo de contacto”… This is what I thought but I have some people advising me in Spanish who are suffering from the Dunning Kruger effect. They swore up and down that it is a different term in Spanish. I have finally found some proper help.
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