[Mayday]

Rather than thickening to a gel, what about using dropper bottles? Plus a small amount of Xanthan Gum or else for spreading the drops better.

[Mayday]

MarkBroussard said:

[…]What this also proves is that the majority of consumers like the new formula at least equally as well as the original formula.  So, how is it possible that the “naturally” formulated product is “subpar” to the formula with synthetics and a “step back”?[…]

My gripe is with highly effective products being discontinued and replaced with slightly inferior formulas. I understand it’s being done due to market pressure, but when that pressure is caused by misinformation and/or the naturalistic fallacy, I do find it unfortunate. (Nature being neither good nor evil, simply exists: filled to the brim with suffering, striving, living things.)

Another such example is the recent Cetaphil reformulation that is no longer compatible with my mother’s skin.

Please don’t think I’m missing your point, however. At the end of the day, what matters is not ultimately the technical performance of a chemical formulation. It’s how using the product alters the subjective conscious experience of an individual to make their life better. This can be by technical excellence, though it doesn’t have to be.

It’s not just cosmetics. What’s even the point of food? If it were only about survival and efficiency, we would eat some slurry that maximizes nutrition and minimizes cost. Clearly, most of us don’t want to live like that.

I find it amusing that I often find “healthy” food to be subjectively more enjoyable than junk food. Why? Not actually because of the taste and smell. Junk food may trigger a dopamine hit, but it is quickly followed up with negative feelings of guilt and disgust. Healthy food may not taste as good in the moment, but it comes with feelings of wholesomeness and virtue. And those feelings are trained by what I think I know about nutrition.

I posit this is the way many consumers experience using cosmetics, based on what they think and feel about ingredients/packaging. And it is very unfortunate that their feelings about ingredients are often misguided by fear-marketing and sensationalized news. Mine were too, before I started here!

[Mayday]

There’s at least a few consumers who prefer highly effective products over “naturally” formulated ones. Some reviews from Nivea’s reformulated lip balm:

Unfortunately, judging by the overall reviews, most consumers seem to be happy with a subpar substitute that “aligns with their values” and is psychologically comforting.

It’s one thing if a natural formulation is substantially equivalent in performance. It’s another when it’s a step back.

[Mayday]

PhilGeis thank you for pointing out that section.

@drjayseesunish said:

Another well known name is Arial; developed by P&G.  Its liquid detergent not mentioning single ingredient except instructions to use it.

Laundry detergent is not a cosmetic product, so cosmetic labeling regulations do not apply. Unless I’m mistaken, neither is dish detergent. From FDA.gov:

The Federal Food, Drug, and Cosmetic Act
(FD&C Act) defines cosmetics by their intended use, as “articles
intended to be rubbed, poured, sprinkled, or sprayed on, introduced
into, or otherwise applied to the human body…for cleansing,
beautifying, promoting attractiveness, or altering the appearance”
[FD&C Act, sec. 201(i)].

This article mentions that other regulatory agencies have their own rules that apply to noncosmetic chemical formulations depending on their intended use (OSHA/EPA/etc.).

With respect to BIOTIQUE… From their website, it appears they are an Indian company subject to India’s regulations and birthed from Indian business culture[1]. They do not appear to have retail stores in the US or the EU. Have you seen their products sold on store shelves at your location? From their site:

All Domestic & International orders shipped from our New Delhi warehouse and will take their respective time in delivery.

Globally they seem to operate by direct-to-consumer ecommerce, which would make it difficult for the FDA to regulate imports of these products. It’s up to the Indian authorities to enforce their own regulations, and what they are doing now is what they can get away with in their regulatory environment.

[1]: If you want to be scared to ever again take generic drugs, listen to this podcast episode about Ranbaxy’s fraud in the pharmaceutical industry. If blatant fraud was occurring on this scale in pharma, I expect the Indian cosmetics industry would be worse. No offense intended to those individuals and companies in India who produce safe, high-quality products, and do not engage in such fraudulent practices.

[Mayday]

MarkBroussard said:

@esthetician922

You can’t … you must disclose every single ingredient in the product regardless of how little you use.  The only work-around is if you apply to the FDA for a trade secret, but you must have a valid reason for requesting the trade secret and the chances of you receiving one are very, very slim.  

So while intentionally concealing ingredients is obviously unacceptable, what would you think about the following cases?

1. Carrier solvents, such as the alcohols in fragrances, flavors, etc.
2. Process ingredients, such as residual isopropyl alcohol from sanitized equipment that has not fully dried.
3. Impurities in larger amounts, such as up to 8% diethylene glycol monophenyl ether in cosmetic grade phenoxyethanol. (I’ve only seen this mentioned in the 1990 CIR review for PE. Maybe not a great example anymore since no Phenoxyethanol COA I’ve seen has this.)
4. Impurities/additives in small or minute amounts, such as 0.04% Silicone Dioxide (anticaking?), and 1ppm Arsenic in MakingCosmetics Titanium Dioxide.

I’m unsure about 1 and 2.

For 3, I think it is too significant not to list.

For 4, it seems unnecessary.

[Mayday]

@PhilGeis  My mistake, the paper was referenced by the CIR review only passingly. “Rationale for local toxicity of calcium chelators” (Urol Res (1992) 20:19-21, W. Oosterlinck).

Oosterlinck 1992 studied the effects of citrate and various EDTA salt solutions (additionally with/without TEA) on inducing bladder lesions in rats.

From Oosterlinck 1992, any amount of calcium chelation (including 100mM citrate + TEA) is potentially damaging/irritating to urothelium. The average female urethra is only 3-4cm long with the proximal 2/3 being urothelium—not enough buffer distance from the meatus to make urinary ingress of a lubricant impossible.

The CIR describes EDTA-metal-ion chelates as forming in the order:

• Na+ < Ca2+ < Fe2+ < Co2+ < Zn2+ < Cu2+ < Pb2+ < Fe3+

Calcium Disodium EDTA is used intravenously to treat heavy-metal poisoning (including Pb2+). While I’m not well-informed on the specific chemistry of EDTA chelation, my understanding is that Calcium Disodium EDTA can still complex with the other metal ions starting with Fe2+ in solution.

Re: preservative testing. I will be sure to test preservative efficacy and substitute with a more appropriate system as needed.

[Mayday]

I am actually doubtful now if the slight haze is due to the parabens. Substituting parabens for Sodium Benzoate produced the same effect. I think it is the specific PEG-90M I am using.

What I am more concerned about is if there’s a likely potential for full deactivation (a la polysorbate) between PEG and methyl/propylparaben.

[Mayday]

@PhilGeis thank you for your response!

The sources I have access to list Propylparaben solubility in 25C water as 0.05% (Preservatives for Cosmetics 2nd ed) and 0.04% (a brochure I found). I have perhaps seen it discussed here that paraben solubility may be increased by pre-dissolving it in a surfactant (?) but that is not very applicable to my formulas.

I started with 2000:1000ppm methyl:propyl from your advice on other posts, but was unable to keep the Propylparaben from precipitating when cooled to 25C. I haven’t found a good source for the sodium salts as a residential homecrafter.

Ca NaEDTA is because the CIR Final Report Safety Assessment for EDTA (PRS285.pdf) notes that calcium chelators are toxic to urothelium. My understanding is that the membrane weakening effect of calcium chelation is helpful for boosting preservative efficacy, but so long as the final formula passes PCT I would prefer to make that trade-off.

[Mayday]

At this point I am just nerding out over these things, but I bought a vintage Ohaus NJ-manufactured Triple Beam Balance off eBay and it’s surprisingly accurate and consistent. I’m guessing it’s from the 1970s or so from how yellow and aged the instruction pamphlet looks.

I can’t say if the difference is due to the Ohaus brand, being made in the USA, or due to a time period when mechanical balances were required to be accurate and precise because there were no alternatives. (Or some combination of these factors.)

[Mayday]

I can’t make specific recommendations, but if you’re formulating anything in contact with genitals, you should be aware that there are additional areas of concern that I’ve come across in my own reading.

Osmolarity. pH. Preservative systems hostile to microflora. Calcium chelation and danger to urothelium. Impact of ingredients on microflora, such as oils and sugars. Permeability of mucous membranes to some molecules.

Re: glycerin. I suspect it’s mostly due to popular low-cost extremely hyperosmolar lubes based around glycerin and propylene glycol.

[Mayday]

25% fully dissolved at 6m30s with low speed vortex on magnetic stirrer. Most of it was already dissolved by 5m.

[Mayday]

A bit unconventional, but have you tried no surfactant cleansers at all? I use gentle exfoliation with the palms of my hands under running water in the shower, and that removes all excess oil from my face.

If you are not stripping any oils away, and your skin is still dry, then it’s some combination of age/genetics/environment (nutrition too)—you need extra moisturizer to compensate for inadequate NMF if you can’t correct environmental factors.

[Mayday]

At least 6 hours of stirring on the magnetic stirrer. Added 10% initially which dissolved quickly, then added the rest up to 35%.

Looking at the solubility on PubChem again, I misinterpreted the values. It’s 36.0g NaCl to 100g H20. That’s actually 26.47% NaCl out of 136g total. I have an additional 8.9g NaCl beyond saturation point.

Will try a 25% solution and see if that dissolves properly. If not, 20% will be fine.

[Mayday]

sean9980 said:

Mayday, and what percentage are you using Potassium Sorbate, I haven’t really noticed too much of a smell from the Potassium Sorbate, however I know the smell of the Phenoxyethanol is quite strong. I am going to try 0.5%, have you had a mostly water based system and done PET on it?

0.15% KSorb and 0.35% NaBenz adjusted to pH ~4.2 with HCl.

Informally, neither KSorb nor NaBenz had an odor at neutral pH. After activating with HCl, only KSorb had an odor. This may just be my specific sample from Organic Creations. However, my current opinion is that sorbate may be more trouble than it’s worth due to flushing reactions, oxidation, yellowing, and possible pungent odor—compared to benzoate.

Likewise, my Phenoxyethanol does not have much noticable odor. If yours does, I suggest sampling other suppliers for one that better suits your product.

Also I agree with Abdullah above. Sodium Benzoate is likely better. But formula must be pH adjusted appropriately for the benzoate to be useful.

I expect if your pH is above 5.0 the benzoate will not be an adequate preservative unless you add excessive amounts.

[Mayday]

I do not get much of an odor with 0.5% Phenoxyethanol or Sodium Benzoate (both LotionCrafter).

I do get a sharp and pungent acid smell with Potassium Sorbate (Organic Creations) after activating with pH adjustment. 

[Mayday]

pK_a is mathematically derived from the K_a, or the acid dissociation constant. It doesn’t make any sense for your overall formulation to have a pK_a, since that is used to describe the strength of a single acid in solution. There may be a miscommunication as to what information they want about your formula.

[Mayday]

Mayday said:

I think if the paraben is fully dissolved (not a slurry) in the solvent, then as long as that solvent is in turn miscible in water (or soluble at that level), it should not precipitate out.

I now think this conclusion is incorrect given others have reported problems with precipitation while diluting a paraben stock with distilled water. My new thinking is that unless you have surfactants to help keep the parabens in solution, the solubility will be more-or-less the solubility of the main solvent (water) rather than the stock solvent (phenoxyethanol/ethanol/propylene glycol, etc.).

Given the solubility limit of propylparaben in water at 25C is 500ppm, it’s likely the propylparaben that is precipitating out of solution as it cools. Phenonip’s solubility limit of 0.5% in water (at 25C? Brochure doesn’t say.) gives individual paraben concentrations far below the solubility limit in 25C water, and a total paraben concentration of only 1400ppm.

Getting 1000ppm propylparaben into an aqueous solution without surfactants would then require either a correspondingly large proportion of cosolvent (propylene glycol, etc.) or using sodium propylparaben with pH adjusted below 6.

[Mayday]

An idea, more directed at OP though: why not treat the aloe as a food product? Put it in a jar, pasteurize it, and have instructions to refrigerate after opening and a recommended shelf-life. Sodium Benzoate or Potassium Sorbate and pH adjustment to activate it should extend the shelf-life in the fridge as well.

[Mayday]

@Pharma Thanks so much for the explanation!!! I really appreciate it. I think I understand well enough, though this is the first I’ve heard of the octanol/water partition coefficient.

My chemistry schooling is just high school and one college chemistry class a while back, and I don’t think we covered these topics. I’m trying to fill in the gaps in both directions: bottom up (fundamentals) and top down (questions like these, relevant to functional cosmetic chemicals).

[Mayday]

I think if the paraben is fully dissolved (not a slurry) in the solvent, then as long as that solvent is in turn miscible in water (or soluble at that level), it should not precipitate out.

I have not been able to find information about, e.g. solubility of methylparaben in phenoxyethanol. I think these sorts of mundane but difficult to answer questions are why people hire experienced cosmetic chemists. Sometimes I can find hints in research papers (…thanks to Miss Elbakyan).

[Mayday]

Water-based personal lubricant, so it is only the water phase. Still testing gelling agents, but want to get a working preservative system defined before doing more work in that area. Not for commercial purposes at the moment.

[Mayday]

@ketchito @Bill_Toge thanks

I had completely forgotten about ionic disassociation in this context.

[Mayday]

Thank you for that table. It’s good news, actually!

How I read the table: 1g EDTA-39% solution chelates 156 mg CaCO3. So if we had pure EDTA, 1g EDTA chelates 400mg of CaCO3.

(Then to see how related by moles… Assuming tetrasodium EDTA—else how are they getting it into the water? 0.2630mmol EDTA to 0.3996mmol CaCO3 means 1 molecule of tetrasodium EDTA chelates 1.519 molecules on average of CaCO3.)

In my case, my tap water is 156 mg/L CaCO3. So need 0.39g/L to chelate, which is only 0.039% (390ppm).

[Mayday]

Depends on the level I think.

According to my municipality’s water report, my tap water is 156mg/L CaCO3. Assuming 1mol EDTA can chelate 1mol Ca2+ ions (maybe wrong, too conservative?) gave me 0.07% (700ppm) Tetrasodium EDTA when I did these calculations a while back.

Water hardness charts seem to top out at 180 mg/L but I bet there are places  with much higher levels all grouped into the “very high” category.

There’s also lead and copper that could be in the water as well from the pipes, probably at much lower levels though.

[Mayday]

Abdullah said:

My plan was to solubilize IPBC in phenoxyethanol and then add it to formula. There are 1%,2% and 10% IPBC in phenoxyethanol commercially available so solubility would not be a problem. What i wanted to know was that which one is better value for money . 0.2% methyl Paraben is better value for money than IPBC if they are similarly effective. 

If IPBC is less than 20x more expensive than methylparaben, then the IPBC would be more economical because it’s only 100ppm vs 2000+ppm. Methylparaben by itself may need to increase the concentration (to 3000ppm?) if you can’t pair it with other parabens.

I still think I prefer methylparaben because of its lower irritation potential, more widespread use in cosmetics/food, and better biodegradation.

Suggestion: Phenoxyethanol@0.5% + Methylparaben@0.3% + Disodium EDTA@0.2%

“Preservatives for Cosmetics 2nd ed.” says 0.1% free acid (0.2% Disodium EDTA) is optimal for preservative boosting. However, if the main mechanism is in chelating calcium from microbe cell membranes to weaken them, then your water hardness will make a big difference in effectiveness. The more calcium carbonate in your water, the more EDTA you will probably need.

DMDM Hydantoin usage is up to 0.6% in EU.