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Forum Replies Created
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Since antidandruff products fall in the pharma realm and according to the laws in your country, you should consider ingredients approved by regulatory agencies. For instance, this is FDA’s monograph for antidandruff ingredients: https://www.accessdata.fda.gov/drugsatfda_docs/omuf/OTC%20Monograph_M032-Drug%20Products%20for%20the%20Control%20of%20Dandruff%20Seborrheic%20Dermatitis%20and%20Psoriasis%2012.16.2021.pdf. You can also check the european database (Cosing), and there you could add Climbazole and Piroctone olamine to your options. All of these ingredients have decades of clinicas studies that support their safety and efficacy.
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If by GRAS you mean Generally Recognized As Safe, I haven’t found any terpene in that list. Could you please share the essential oils calculator? There’s so much deviation in natural oil’s compositions, that I’m curious to know what they are calculating 🙂
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Manufacturers of Copper PCA mention it as being an antioxidant. Color change can be linked in this case to an oxidation process. If that’s the case, it would actually be doing its job (being oxidized instead of some other molecule), so perhaps this is not an issue.
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If you’re evaluating mixtures of chemicals, you might have a hard time interpreting the results. Even with single chemicals, you’d need some reference, so be sure to search for the right literature (both for procedure -to know which column to use, if you need to pre-treat your sample before- and results interpretation).
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I’d try to pair emulsifiers with a bit more similar structure so lamellae has better packing (the sucrose in your sucrose stearate might have a negative steric effect).
By the way, what is SS? ???? I’d also increase viscosity of your water phase (HEC might work, but I prefer something with emulsifying properties, like Structure XL….or even Natrosol Plus 330).
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Your regular emulsion has a high viscosity because you got a complex micellar arrangement (worm-like or rods, that can even be entangled). When you introduce hydrocarbons, they go to the core of your micelles and cause a transition from worm-like (viscous) to spherical (non viscous). Just a question, are you emulsifying the hydrocarbon with the whole oil phase? Or adding it after?
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I remember Dr Wichers did a lot of research on humectants, especially on glycerin. He found that it has properties beyond its ability to capture water, and part of it was due to glycerin being able to penetrate few layers of the SC. That wouldn’t be possible is you make a polymer out of it (maybe an oligomer). So, I’d stay with our very old friend the way it is.
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It’d be better if you post your formula, but withor much information, it could be an oxidation issue. You could add some Tinogard TL.
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Since the first one is from P&G and the second from L’oreal, chances are they are using microemulsions which don’t cream as macroemulsions, not requiring a super efficient suspending agent.
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Did you check if there was a pH drift in the bottles that showed discoloration compared to the others?
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You could add Cocamidopropyl betaine plus either DEA cocamide or PEG-4 rapeseedamide.
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@sundae3 As @Abdullah mentioned, it’s hard to get a stable product using a Glucoside surfactant and HEC. If you still want to try, you could add some base after HEC (which should be added first and let hydrate) to help dissolve its envelope, and then add coco glucoside…and see how it goes, but there’s not much hope based on experience. Don’t you have any anionic surfactant around?
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@BathroomChemist just out of curiosity, how do you confirm you’ve got a microemulsion? Did you use some microscopy or diffraction technique? Did you get a blue-ish look on your serum? Usually for stable microemulsions, the use of small alcohols and specific surfactants are needed (unless you use linkers and many other funny stuff to get the required curvature), not to mention the type of oils in your oil phase…so having only polysorbate 80 as sole surfactant intrigued me. Good luck!
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If your manufacture is at the industrial level, then you should focus on the pipes, joints, everything that a regular sanitization process won’t cover and where there would be a change to biofilm formation.
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Dear @MikeThair,
With all due respect, I doubt you actually read those references. Just few comments on the ones you mentioned:
1) Parabens as chemicals of emerging concern in the environment and humans: A review: this one has many biased comments, like saying that preservatives use will increase in the comming years because consumers want products with higher shelf life (if that was the case, many of the newer “natural options” wouldn’t be even considered). They also mention many times the works from Darbre and how he showed a relationship with breast cancer (studies that were heavily criticized by many experts, due to the poor study protocols; similar -but correcting Dabre’s flaws- studies conducted later on showed no link).
2) Paraben Toxicology: in its very abstract, they actually are IN FAVOR of keeping parebens: “Based on currently available scientific information, claims that parabens are involved in the genesis or propagation of these controversial and important health problems are premature. Haste to remove parabens from consumer products could result in their substitution with alternative, less proven, and potentially unsafe alternatives, especially given the compelling data supporting the lack of significant dermal toxicity of this important group of preservatives.“
3) Preservatives in non-cosmetic products: Increasing human exposure requires action for protection of health: reading that paper, I was shocked by the mention of Bronopol (risk of nitrosamine formation) and Formaldehyde as the most used preservatives…but then I noticed the paper was about non-cosmetic products, hehe. Weird thing that they talk about preservatives for non-cosmetic use, but they use cosmetic regulations to show their permitted level.
While it’s nice to have a peer-reviewing process to filter information in a scientific paper, this process is not always correct. You might want to read this: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1420798/. We’ve seen so many times flawed studies being published in BJM, Nature, NEJM and few more of the big journals, that had to be retracted, or that were found to use very weak evidence to draw conclusions. This is why having specialists (I cannot stress this word more) in the CIR or SCCS to review the evidence and take only the one that has a stong methodoly and less risk of bias, is crucial.
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I wouldn’t rely on supplier’s data. You might want to check this: https://pubmed.ncbi.nlm.nih.gov/3711890/
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You need to make sure that both water and oil phases are few degrees above the highest melting point of your ingredients. Also, mixing should be vigorous when you combine both pases. And I’d choose a different emulsifier (like ceteareth-20, for instance…Mineral spirits would be hard to emulsify due to its very low polarity).
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@Abdullah Keep in mind that at low pH, cations (specially small ones) compete for binding sites with H+. That’s why you see that behavior shown in the graph. That shouldn’t be different if you had Phytic acid (I found a paper mentioning that no significant binding from Phytic acid to Ca2+ was found at pH lower than 5. The binding of group d metal ions (like Fe2+ and Cu2+) has the advantage of both relative cation size and back donation, which make complexes more stable.
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You could consider also MGDA or GLDA (although, at the pH you require, MGDA might be more appropiate).
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Bu Castor oil, do you mean PEG-40 hydrogenated oil? The last one is a solubilizer, and is usually chosen in these type of products. If your body mist has alcohol, then up to some level you won’t need a preservative (although, as previously suggested, you’d need to micro test your formula). Now, with these products you need to ensure solubility, UV light and oxidation stability due to the high fragrance content (compared to other water base formulas). You might need to add a UV filter and/or an antioxidant.
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Hi Mike,
Apparently the PCPC is hosting the reports from CIR, but the image I uploaded is from the CIR report for parabens, you might want to take a look to confirm. As I mentioned, both the CIR and SCCS reports are amongst the most trusted source of information when it comes to evaluating safety of ingredients. They for sure looked at the hundreds of reports you mentioned and selected the ones that had less risk of bias and had the strongest methodology. It’s a very fun read ????
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Just out of curiosity, did you get this info from ChatGPT or similar? I’m asking because it lacks some important points (like the influence of the type of product on each preservative system’s efficacy) and some others are unsupported (the type of parabens approved for cosmetic use were over and over proved to be safe).
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@BathroomChemist Sweet! Back in the day I had a very nice microemulsion for a laundry detergent. I didn’t have small alcohols at hand (pentanol and hexanol are used quite some in papers I found), so I used gasoline instead (I know, I know…not something you’d have in your bathroom) and it worked! I also used octyl disuccinate as hydrophilic linker. Nevertheless, I never managed to increase its viscosity without altering the system, so I drop the formula. Good luck with your project!
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Would you kindly share some of those peer-reviewed papers showing the endocrine disruption from preservatives in cosmetics? My understanding is that in the case of preservatives, the conversation goes the other way. If you check CIR and SCCS reports, they review avalialble evidence for, among other things, endocrine activity, and put it in perspective (they model exposure). Here’s the CIR report for parabens: https://online.personalcarecouncil.org/ctfa-static/online/lists/cir-pdfs/PRS746.pdf. In page 36S (very weird way to number pages) there’s the endocrine activity part. You’ll see that not only parabens have a very weak binding affinity to endocrine receptors (Methylparaben’s binding affinity is not even detectable), but they have thousands of times less potency than natural E2 (again, Methylparaben even fails to show any activity in some studies). This is the type of information safety reviewers check before recommending the safe use of (in this case) parabens as cosmetic preservatives. I understand we can have different opinions, but when there’s clear evidence about some hot topic, we need to show consensous….otherwise, fear mongering and missinformation will win the battle.
