Forum Replies Created

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  • evchem2

    Member
    July 2, 2025 at 7:38 am in reply to: Comedogenic Testing Lab

    I haven’t performed this kind of testing before, but it makes sense it would be “extremely expensive”. As far as I’m aware, the testing methods for this are either on rabbit ears (obvious ethical concerns, and less obvious validity/extrapolation issues) or human subjects. You may need to substantiate that the product is not irritating before comedogenic testing which would add additional cost. These studies involve reapplication over a period of weeks which increases the cost as well.

    The term itself is loosely defined and personally, I don’t think it’s worth the cost of testing. Here are some related references that explain better:

    https://labmuffin.com/fact-check-how-to-use-comedogenicity-ratings/

    https://pmc.ncbi.nlm.nih.gov/articles/PMC8387765/

  • evchem2

    Member
    June 5, 2025 at 8:01 am in reply to: 2in1 Shampoo & Leave On Conditioner

    I don’t think it’s possible to have a leave-in conditioner product that also truly cleans hair. When you say “cleansing effect” do you just want the hair to look clean or to actually have soil removed? There are a few ways surfactants remove oil/particulates, but rinsing is a critical step no matter how the soil is separated from the hair/scalp. If you don’t rinse out the hair, how else will you physically remove buildup?

    Leaving too much surfactant on your hair/skin without rinsing is likely an irritation risk. If this is for anything other than personal use, check your regulations. For a leave on product in the EU, Cetrimonium Chloride use level must be <1% (https://ec.europa.eu/growth/tools-databases/cosing/details/32590) , in the US the CIR recommends <0.25% (https://cir-reports.cir-safety.org/).

    If you just want to mimic the appearance of clean hair that might be possible with the right conditioning agents, maybe some starch to absorb excess oil.

  • evchem2

    Member
    June 3, 2025 at 9:46 am in reply to: 2in1 Shampoo & Leave On Conditioner

    I would suggest looking at 2 in 1 products already in the marketplace- the technology for combining a shampoo and conditioner usually relies on conservation and dilution/deposition, which for these systems typically involves an anionic surfactant and a cationic polymer. You don’t have either- you have some nonionics, an amphoteric, and a cationic surfactant. Look into coacervation technology and what other major brands are doing.

    Just for your reference, I would still call a 2 in 1 product a rinse-off, not leave on (users will always need to rinse out the shampoo, the hope is your formula is able to leave behind some conditioning agents).

  • evchem2

    Member
    May 15, 2025 at 7:34 am in reply to: Cream Pilling - need help

    A few thoughts:

    -try solutions of just your polymers at the target use level to see if those pill

    - try a sample of the cream without colostrum to see if the gelation still occurs.

    How is the colostrum treated before you incorporate it to lower microbial burden? Based on the ingredient listing of your benchmark, I believe (hope) the colostrum is used there at <1%. I would keep yours at similarly low levels- it seems like a risky ingredient to incorporate for a few reasons.

  • evchem2

    Member
    April 29, 2025 at 7:45 am in reply to: URGENT - My manufacturer is short an ingredient need substitute

    2kg short for what batch size?

    The procol SDS I see lists the blend as ~20% ceteareth-20 (not sure you can/should try to substitute that out), and ~80% cetearyl alcohol. That 80% you could replace with cetyl and stearyl alcohol, usually in a 30:70 blend respectively. So 480g cetyl, 1120g stearyl to add to your batch, hopefully that helps.

  • Based on the fact water is after tocopherol, I would guess the water is <1%. Lecithin is the only emulsifier I see here, but the xanthan gum (though this might be low % /part of an ingredient blend) and waxes can also contribute to stability

  • You could try adding a fixative (like triethyl citrate), but I don’t know how well that will work- what temperature will your product be used at? I’m also not sure how much you could reduce the fragrance volatility without impacting perception/scent intensity- that volatility is what helps the fragrance molecules reach our noses’ receptors. Your test looks like a much larger quantity than would be used in real life- if you try your product on some hair extensions can you even see the vapor/smoke?

  • evchem2

    Member
    March 10, 2025 at 7:46 am in reply to: Electrolyte tolerant polymers

    Plenty of natural polymerics (xanthan is a good example), some even gel or get increased viscosity in the presence of electrolytes (gellan, carrageenan) . If this is for a rinse-off formulation, something like carbopol aqua sf-1 polymer (acrylates copolymer) will help thicken in presence of salt.

  • evchem2

    Member
    March 4, 2025 at 7:32 am in reply to: Glass VS Plastic containers for skin care

    Yes I think the packaging needs to tie into the branding, but that’s not all to consider. Are you selling locally or will the product have to be shipped? Glass is heavy and runs the risk of cracking. Where will the product be used? Most brands avoid glass for shower/rinse-off products. The heft of glass does seem to signal a more premium product, but if you look at top brands like Olay or some of the leaders at sephora, they don’t all have glass packaging. I think the packaging needs to be functional above all, but the aesthetic is a good driver for people initially considering the product.

  • evchem2

    Member
    February 28, 2025 at 7:35 am in reply to: what can I not use with xanthan gum?

    @fedaro is right on the cationic incompatibility- sometimes you can overcome this by including a high amount of salt (>2%) in a formulation and adding the polymers far apart from each other in the process, but that comes with its own issues.

    Other than cationics, xanthan is pretty tolerant of many situations and ingredients. There are a few unique situations I can think of- for example, some xanthan gum is treated with cellulase to clarify it, so if you are using a cellulose-based polymer in a formula with xanthan gum you should ask your supplier about cellulase activity. In high pH (~9+), xanthan can gel in the presence of polyvalents like Ca2+ or Al3+.

    What you described sounds like an issue with dispersion of the gum. You can either use high shear to break up any clumps, or next time try creating a premix of xanthan gum in a polyol like glycerin before you add it to the water.

  • evchem2

    Member
    February 25, 2025 at 9:24 am in reply to: WHAT IS THE SAME FORMULATION MEANING

    Are you asking if it’s the same formulation from a regulatory standpoint? What country are you selling into?

    I would not call a formula with different ingredient levels the same, but if this is for a finished good/rework of a formulation you can measure certain attributes (viscosity, pH, stability,etc) and determine if the new formula would still meet your release criteria- hope that makes sense.

  • evchem2

    Member
    February 24, 2025 at 12:13 pm in reply to: cosmetics manufacturing management softwares

    I’m not familiar with any of the software you mentioned- couldn’t even find the third one. Cosmedesk looks more limited compared to Cosmetri. I’ve used Formulator software (https://www.formulatorus.com/index.php/industry-page/cosmetics-catpage) in the past which I think has enough functionality to cover many aspects of R&D and production at small scale. I don’t know exactly why but at my old job we eventually transitioned away from this software for production and just moved to SAP for that (might have had to do with paying formulator for user licenses and/or the software wasn’t set up to handle our distribution activities)

  • evchem2

    Member
    February 5, 2025 at 8:04 am in reply to: Warming Effect personal Lube / Lubricant

    Just as a disclaimer- personal lubricant does not fall under US cosmetic definition, you need 510(k) clearance which involves pre-market approval of safety (if you are selling to US market).

    Personally I would avoid ‘functional ingredients’, unless you have strong evidence of the safety of each component individually and as a combination for the specific areas of application.

    Are you actually getting any viscosity build from the PQ-7 in polyols? What is ‘stabilizer’?

    Glycerin can produce a mild warming effect when it comes in contact with water- this requires the formula to be mostly anhydrous to start though. I’m assuming the PQ-7 is a solution so you are adding water already, and I’m not aware how safe a polyquat is for vaginal tissues, haven’t seen a polyquat in lube before.

    I have tested methyl nicotinate before for a different application- it certainly produces warming. I would start with a low amount (0.1-0.5%), I’m not sure how well it will be solubilized in a polyol base.

  • evchem2

    Member
    January 17, 2025 at 8:19 am in reply to: Scalp serum (O/W emulsion) FAIL! PLEASE HELP!

    I would recommend adding xanthan and acacia earlier in the process, ideally before you add anything else- you are adding them after salts and that can inhibit full hydration. I’d reduce your tocopherol to 0.1% as well, it’s too high. You can also try adding just your oil phase to water (without the salts and polymers) and see how quickly that mixture separates. If it’s pretty fast you might need additional solubilizer or emulsifier- I’m not sure the walnut oil can be solubilized by the symbiosolv.

  • evchem2

    Member
    January 13, 2025 at 12:13 pm in reply to: Xanthan gum in toothpaste?

    I work for a manufacturer of xanthan gum (not TIC). For us the difference between cosmetic grade and food typically comes down to micro spec- lower for cosmetics than it is for food. There may be some additional tighter specifications but the bioburden is usually the main concern and cost is higher as a result. We also sell a ‘smooth flow’ xanthan that has reduced stringiness that @Herbnerd is mentioning- this is a slightly different polymer from the standard xanthan, but it’s still xanthan overall.

    What works ‘best’ will come down to your processing/application needs. Xanthan can have variance on the properties that can be produced for certain conditions -some are more salt tolerant, some have high thickening efficiency (usually at the expense of appearance/ stringiness), some grades we ensure are cellulase free which is beneficial in toothpaste if you are also using CMC, etc. Feel free to DM me or provide more detail on what ‘best’ means to you in this case.

    • This reply was modified 5 months, 3 weeks ago by  evchem2.
  • evchem2

    Member
    January 6, 2025 at 7:34 am in reply to: What is RSSL( relative surface silicone deposition level)

    I’m not familiar with this term but if it’s relative it may be an index range compared to some standard. Can you cite the paper you are reading so we can get more context?

  • evchem2

    Member
    December 4, 2024 at 7:31 am in reply to: Summer Internships Inquiry

    You can look into the society of cosmetic chemists and ask your local chapter if they know of any openings, or search their careers website.

    https://careers.scconline.org/

    You can also look for large brands and check their linkedin for potential internships, for example Henkel is currently looking for an intern in laundry development.

    https://www.linkedin.com/jobs/view/4080266210/?capColoOverride=true

  • evchem2

    Member
    July 3, 2025 at 7:08 am in reply to: Comedogenic Testing Lab

    I understand! You should absolutely have substantiation for claims, for both ethical and legal liability reasons. My point is that the specific claim of ‘non-comedogenic’ will probably be inherently expensive to test in any meaningful way. Like I said I haven’t had this test performed before, but CPT labs offers it if you want to get a quote https://cptclabs.com/comedogenicity-and-acnegenicity/

  • evchem2

    Member
    June 16, 2025 at 12:08 pm in reply to: 2in1 Shampoo & Leave On Conditioner

    My concentration is skincare, not hair, so I’m not the best resource for suggestions. Very generally, cationic polymers help reduce frizz. I’d just look at market products because I can’t advise if Polyquaternium-7 vs 10 is better for a given hair type from personal experience. There are articles and previous forum posts that would offer more insight (https://chemistscorner.com/what-is-polyquaternium/) . But some cationic surfactant and the right oils/silicones could probably also support frizz reduction and help with shine.

  • evchem2

    Member
    April 25, 2025 at 7:08 am in reply to: Scalp serum (O/W emulsion) FAIL! PLEASE HELP!

    Pretty much the entire phase C, but especially the Sodium Ascorbyl phosphate and Pyridoxine HCl

  • evchem2

    Member
    January 30, 2025 at 7:45 am in reply to: Xanthan gum in toothpaste?

    Can’t speak for all xanthan manufacturers, but I think in theory you could use cosmetic grade xanthan in food.. it would be more expensive ketchup compared to just using food grade. For our food grade SKUs we ensure they comply with necessary regulations in a given country/FCC standards for example. Different grades of xanthan have different specification ranges & unique tests based on the final application. Hope that answers your question

  • evchem2

    Member
    January 17, 2025 at 8:28 am in reply to: Xanthan gum in toothpaste?

    glad to help! And yeah I agree with giving your preservatives the best chance to work by limiting incoming microbial burden wherever possible.

  • evchem2

    Member
    January 17, 2025 at 8:26 am in reply to: Xanthan gum in toothpaste?

    sorry my wording was unclear 🙂 Less microbes allowed for the cosmetic grade since the shelf life is usually longer than food requirements. For example, one of our food grade xanthan gums has a spec of <2,000 cfu/g bacteria. The equivalent cosmetic grade is <1,000 bacteria cfu/g, and we have customers who request even lower levels.

  • evchem2

    Member
    January 15, 2025 at 8:02 am in reply to: Will Carbomer 940 thicken my shampoo?

    I hope it’s okay to ask here but are there not any issues or complexing concerns when combining carbopol (anionic polymer) with the polyquats? Does it come down to the ratios or charge density?

  • evchem2

    Member
    December 19, 2024 at 7:35 am in reply to: Xantham in mass production - plz help!!

    ^This is basically what it comes down to. If you’re going to use a dispersant, general recommendation is to use at least 3:1 ratio dispersant to gum. Glycerin is a bit more viscous than some other options like propanediol that may be easier to mix. You just want to ensure there are no dry clumps of xanthan, it should all be coated in dispersant. I would not recommend adding any water to the premix if you go this route, and you may not want to leave the premix sitting out for too long or it could pick up moisture from the environment.
    If you have high shear mixing capability, you can skip glycerin since it’s probably not benefitting your shampoo to have it. Just sprinkle in the xanthan gum to the water directly and mix vigorously, you could also heat slightly to help hydrate the gum (and slow mix to help get out any air you may incorporate).

    Process should be: xanthan (premixed with glycerin if using)> add to water, let mix (anywhere from 5-15 minutes is my guess)> add preservative/surfactants

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