[letsalcido]

@africanbug yes, some ingredients can be pH sensitive and their reactions may not be reversible. But it will really depend on the ingredients and will need to do due diligence to understand each of them in your formulas.

One thing to consider too is the localized pH, if you’re using a highly concentrated acid or alkaline solution you‘ll want to adjust your pH before adding the sensitive ingredients, otherwise the are where the drop of solution enters your formulation will shoot up/down and destroy some of your sensitive material.

If the ingredients also change the pH, you should also consider a buffered formulation.

[letsalcido]

@ozgirl I did read about occupational asthma from quaternary ammonium compounds. I suspect at the low concentrations used in household products the risk is incredibly low? I would be most concerned about bacterial resistance. I have more to read and learn about these compounds obviously.

@Perry do you think the technology is stale because of lack of research or because we are approaching a “saturation” point? Similar to other industries: Moore’s law for computer processors, and uncanny valley for graphics. 

[letsalcido]

@Perry as a consumer, this kind of information makes me nervous. Even having the education necessary to dig deeper and read studies about those ingredients there’s always a seed of fear planted by these. 

[letsalcido]

@esthetician922  it’s not the type of blender, it’s whether the blades can be deep enough in the liquid to prevent introducing air. Also, moving the blender up and down will introduce tons of air.

You can introduce xanthan gum while stirring with a rod or paddle if you’re making a small batch. You do need to “slurry” the xanthan with glycerine to avoid clumping.

if you’re going with powder high molecular weight hyaluronic, at 1% you’ll have good viscosity but it will still have some flow to it, so eve if you introduce air it should eventually come out and this powder definitely needs more rigorous mixing, so using the stick blender is fine.

[letsalcido]

@dmh0023 to clarify what ngarayeva001 said:

Cera bellina has a melting point of 65C when pure. When you combine it with your oils, the melting point will change, your specific mixture of oils based on what you said melts well below 50C. By adding more wax or butters with higher melting points you can drive up the melting point of your mixture, thus preventing it from turning soft or partially liquid in your bathroom, car or purse at warm ambient temperatures.

You can increase the percentage of cera bellina, or add other higher melting point waxes to it (like bees wax or candelilla wax). This is was ngarayeva001 recommended, not to heat up what you currently have to 65C.

You should only need to heat up your ingredients enough to turn liquid and be able to mix them thoroughly. If 50C achieves that for your mixture, than that’s perfect. Just mix thoroughly for a minute or two.

[letsalcido]

@esthetician922 this seems potentially more of a physical rather than chemical change.

Highly viscous liquids will trap air and not let go of it. Xanthan gum creates that effect: at low shear the liquid behaves kind of like a solid at high enough concentrations. This is why it is a great suspending agent. 

I have a feeling that you introduced the Xanthan Gum with vigorous mixing (potentially a stick blender?). This will cause tiny bubbles of air to get trapped in your serum. It will be practically impossible to get rid of them once that happens. This will also make it look white and foamy.

I know you had a separate post where you mentioned this “liquid hyaluronic acid”. Just to clarify, pure HA is a powder. Viscosity is linked to the molecular weight of the HA and how much you’re using. High Molecular Weight HA will make gels like Xanthan Gum does, and it will also remain on the surface of the skin (forms a film) for hydration. Smaller molecules will travel a bit deeper into the skin and will also not thicken a product as much.

You’re using 1% of an already diluted version of HA. Do you know what concentration the original is? Note that 1% high molecular weight hyaluronic acid is pretty thick. Like I mention in the other post, you should investigate the concentration of HA in that stock solution because if it’s 2 or 3%, you’re essentially making a serum with <0.03% HA, so basically just water and panthenol with a preservative. Let’s say it’s 2%, your serum would need to contain 50% by weight of the solution to have a final hyaluronic acid concentration of 1%.

As your formula stands and if this is for your own use, you may be better off using Xanthan to thicken some water with 1-2% glycerin instead of that “liquid” HA.

[letsalcido]

@mrlv90 like ozgirl mentioned you should share your formula!

@gomorrian trapping a preservative in micelles doesn’t sound like a good idea. If phenoxyethanol is actually causing the cloudiness and it does get solubilized by PS20, then it will reduce the effectiveness of the preservative.

Phenoxyethanol is miscible in water up to < 3%, and the maximum allowed usage in cosmetics is 1.1%. I am doubting it’s due solubility issues but rather an interaction with other ingredients.

[letsalcido]

https://www.makingcosmetics.com/Provitamin-B5-d-panthenol_p_318.html

Possibly it’s the same manufacturer as the one commercialized by makingcosmetics. It says it uses D-pantolactone (same INCI?) as preservative/stabilizer and the pH is high too 8-9.

[letsalcido]

Yes some of them do, others don’t. It depends on the specific surfactant and whether it has moieties that like to donate (acids) or take (bases) protons. The manufacturer will normally disclose the pH that surfactant gives at a given dilution. Best to simply use a pH meter and check your formula’s pH.

I recommend you do some reading on what pH means, and also look at pKa and pKb. 

You could also take an introductory organic chemistry course if you really want to know and understand why. 

[letsalcido]

Ok, so I made a couple mistakes due to ignorance here. Lingo seems to be a bit different for cosmetics/emulsions when it comes to what is considered polar. I’m not quite sure I like referring to oils as polar. Is this widely accepted in the industry?

Hang with me because I’m about to dump my thoughts here. I’m genuinely curious.

There is no official cut-off for what is a polar molecule. So I guess everyone can choose whatever they like. Even within typically-referred-to-as-non-polar compounds there are some that are “more” polar than others (stronger dipolar moment). Instead of evaluating solubility in water to determine if a molecule is polar, we can certainly say that if a molecule is a dipole the given molecule is polar. Triglycerides could be considered dipoles because they have negative moieties on one side (sometimes) of the molecule, which this seems to be where some of the links above are going. 
Take for example triolein (from olive oil and other natural oils) https://en.wikipedia.org/wiki/Triolein#/media/File:Triolein_Structural_Formula_V1.svg the molecule could be a dipole if all the carbon chains arrange themselves to one side, but in the conformation shown in that link the charges are distributed fairly evenly so there’s probably no net dipole moment. So, as the molecule moves its dipole moment would vary. Chances are steric forces also prevent the negative moieties from interacting with anything, besides them being super stabilized by all the carbons. But I digress.

Consider the example again of isopropyl myristate (17C with 2 O) and octyl palmitate (24C with 2 O), there is no doubt that isopropyl myristate is “more polar” than octyl palmitate. Even the distribution of the carbons support that the dipole moment of isopropyl myristate would be larger with the ester group having 3 C on one side and 14 on the other (the negative charge is towards the side with less carbons), while octyl palmitate has 8 on one and 16 on the other (more balanced, more carbons, less polar). 

@ngarayeva001 the table you shared of Polarity Index (?) is actually measuring the surface tension (as stated in the patent “The relevant interfacial tensions against air are stated in the last column.”). Also, the values don’t make sense to me, compare them to these: http://www.surface-tension.de/ and https://en.wikipedia.org/wiki/Surface-tension_values. Water has a surface tension of 72 mN/m at 20C, not sure where that 10.2 came from. Also, look at the mN/m of methanol and nonane (hydrocarbon) in the wikipedia link, they are indisputably polar and non-polar, respectively but they have almost the same values! Therefore, polarity is obviously not all there is to surface tension (sterics play a role too), and the “polarity index” referred to in that patent is useless and just a rename of surface tension.

(c/c triglycerides is more polar than sunflower oil, based on my experience)

I’m curious, how did you determine that c/c triglycerides is more polar than sunflower oil?

@africanbug  If the ever-so-small polarity of oils (negligible in most context I would say) is destabilizing your emulsion you perhaps need more emulsifier, a co-emulsifier or a completely different compound. Lecithin is a great natural emulsifier (and is biomimetic). You can combine it with sorbitan oleate and you may hit the jackpot. The issue with lecithin though seems to be that it requires high shear emulsification (at least for o/w) but wouldn’t hurt to try. You could also try a secondary emulsifier with higher affinity for water (higher HLB), to prevent “polar” oils from getting close to the oil-water interphase, and to strengthen the micelles. 

@Pharma I saw you posted here https://chemistscorner.com/cosmeticsciencetalk/discussion/355/polarity-of-cosmetic-oils and turns out mN/m  = mili newtons per meter, so it’s measuring surface tension (not quite polarity or dipole moment directly).

[letsalcido]

@ngarayeva001 I think you got the polarity backwards. Vegetable oils are very non-polar. Fatty alcohols and acids are more polar, they have oxygens that can more easily donate a proton/hydrogen bond. I don’t see how isopropyl myristate is non polar and octyl palmitate is medium polarity. Read my explanation below. Octyl palmitate is in fact less polar than isopropyl myristate.

@africanbug to know the “polarity” of a substance you need to understand basic organic chemistry and the chemical groups that are considered polar. 

A simple guidance (not a rule), a carbon compound is soluble or miscible in water (more polar) if it has a ratio of about 5 carbon molecules or less per every -OH (or other highly negative moiety) in the molecule. Take glycerol for example, 3 carbons and 3 OH (1:1) super soluble in water. Other simple examples are alcohols, methanol (1:1), ethanol (2:1) and propanol (3:1) are miscible in water (no limit), but butanol (4:1) is much less miscible, pentanol (5:1) almost non-miscible, and hexanol and up are basically completely non-miscible in water https://www.solubilityofthings.com/water/alcohols

Esters (the chemical group not the cosmetic ingredients) are less polar than alcohols or carboxyl groups because the electric charges from the oxygens are stabilized by the carbons they’re covalently attached to. Triglyerides like vegetable oils are esters, and are absolutely non polar. However, we can’t generalize about all esters because PEG esters (PEG-7 glyceryl cocoate for example) are more polar the higher the number. The number after PEG adds that amount of oxygens and two times that amount of carbons to the PEGed molecule, so you can increase the number to increase the polarity.

If you don’t want to look at molecules all day and try to decipher if it’s polar or not, simply look up if the compound is soluble (or miscible) in water and to what extend. The more you can mix with water, the more polar it is.

Alcohols and surfactans/emulsifiers are absolutely polar, they must be so they can stabilize non-polar compounds in water (or viceversa).

My recommendation is, take some organic chemistry courses online (coursera is a good place to start, or even simply youtube videos), it’s fun and will help you a lot! 

[letsalcido]

@Graillotion I was thinking something like this https://www.amazon.com/dp/B01IXXSWLE/ref=cm_sw_r_cp_api_i_ZrZZEbVZJ5RYP

with this a disperser like this https://www.amazon.com/dp/B0771KTXK3/ref=cm_sw_r_cp_api_i_CtZZEbN7DMXKZ

I made a lotion with a $40 kitchen aid immersion blender that resisted 4 freeze-thaw cycles (didn’t try more) and a week incubated at 55C afterwards. Which tells me you don’t need the highest RPMs to emulsify a lotion, and the disperser disk will give you plenty of shear, plus you can lower the RPM and stir for a long time during cool down with an overhead stirrer.

[letsalcido]

Why not buy an overhead stirrer? Some cheap chinese ones can handle up to 40L (claim by manufacturer), can run for a long time and have adjustable speeds and can definitely handle higher viscosities.

For most emulsions it seems to me that a sawtoothed impeler would be more than enough. A rotor stator will give more stability, but it doesn’t seem to me that your product needs to be shelf-stable for over a year given the small batches. Have you stability-tested your lotions? You can probably achieve the same result with a saw toothed (disperser, medium-high shear) impeller on an overhead stirrer than you do with a regular immersion blender. 

[letsalcido]

You can do whatever you like! 

Hyaluronic acid usage is mostly constrained by cost and viscosity build up depending on molecular weight. Too much can also dry and leave a powdery film or pill on the skin it seems. Some claim that it can have a “drying” effect if concentrations are too high or used in dry climates (take it with a grain of salt).

Only by experimentation you’ll find what the best amounts to use are. Normally you want to use the least amount of a product that still gives noticeable results to keep costs low and profit margins high! 

Worst case scenario: you spend a lot of money on a expensive and trendy raw material. 🙂

When it comes to what is used: 1-2% hyaluronic acid (1% HMW, 0.5-1% SLMW and MMW). But this is just a guideline. The liquid version you have doesn’t specify molecular weights or concentration. If they do, calculate how much you need of that solution to achieve whatever final concentration you want.

[letsalcido]

@Graillotion my limited knowledge ends here, then haha. I hope you can find that perfect scent for your other lotion!

[letsalcido]

Can you hare the formula or at least the process?

Is it perhaps just rinsing the vessel containing another phase just to make sure you don’t lose material when transferring?

[letsalcido]

I personally did not have a good experience with those small mixers for milk frothing. At least the one I bought has too high a minimum RPM and at such small amounts it was hard to keep the rotor far down into the liquids to avoid foaming. 

If you have a bit more budget, try something like this one https://www.ebay.com/itm/282489818954 just make sure the impeller can be bent so it fits smaller containers. Even when extended it should it should fit 250ml beakers.

If you want an upgrade ETE ETMATE Lab Digital Overhead Stirrer Mixer Laboratory Top-Mounted Electric Mixer Digital Display Agitator And Stainless Steel Stir bar 40L 50000mPas 100-240V, Adjustable Feature for Lab Mechanical https://www.amazon.com/dp/B07YX18497/ref=cm_sw_r_cp_api_i_LRlZEbC9AJYD9

One a bit of an upgrade: ETE ETMATE Lab Digital Overhead Stirrer Mixer Laboratory Top-Mounted Electric Mixer Digital Display Agitator And Stainless Steel Stir bar 40L 50000mPas 100-240V, Adjustable Feature for Lab Mechanical https://www.amazon.com/dp/B07YX18497/ref=cm_sw_r_cp_api_i_LRlZEbC9AJYD9

[letsalcido]

@Perry absolutely, I will not dispute the fact that AHAs are absolutely better, safer, more stable ingredient to achieve the same result. I’m not formulating professionally yet, so I’m mostly trying to gain as much knowledge as possible (about bad, good, and best ingredients). And to the point of the post, I supposed we can’t generalize that proteins are useless (as a biochemist I refuse to think proteins are useless ????). Although I guess the main post is about peptides specifically… which yeah I can’t see them actually working unless it was some sort of signaling peptide that can be used to tag liposomes for transport or something of that sort.

[letsalcido]

@Graillotion my first impression is that there is a “small” set of compounds that repel mosquitos and it’s possible that such compounds cause all those EO you own to have similar smells (close levels in the pyramid), like citronella and lemongrass which are commonly used mosquito repellents they have similar smells probably resulting from their overlapping compounds (geraniol, geranyl acetate, contronellal, limonene…).

So, it will be really hard to formulate a balanced fragrance with just mosquito repellent essential oils, because they’re likely a similar set of compounds at different concentrations each. Can always modify the concentrations of each compound to change the character of the fragrance: add sweet orange, grapefruit, lemon, etc to increase lemonene concetration and give a more citrus, light character, or geranium for a more floral scent that simply ups the already present geraniol and geranyl acetate. 

I think looking up what are the constituents of each of the essential oils can help figure out which ones to pair. You probably want a couple compounds that overlap (indicating similar notes) that can “connect” different oils.

I’m no perfumer, but this is what I would do.

[letsalcido]

@ngarayeva001 I’m not quite sure if adding a film former would actually prevent shifting. I guess this is why there’s a lot of testing behind sunscreens and they need to be FDA approved. But if o/w micelles are small enough and remain on the skin, they will essentially be “water soluble” and will wash off. I think the safest route is w/o from a molecular point of view. This is all a gut feeling, I’m not quite sure if micelles would remain or break during application, but I do know certain micellar structures are used for better absorption and transport of actives (some micelles can even be tagged for transport), so I’m assuming the structure remains for at least some time after application.

[letsalcido]

@Pattsi great to know! Thanks for your reply. Now I’m curious whether for somebody with no allergic reactions this would be a “gentler“ exfoliant than AHAs or other acids.

@Pharma so I had to look up what transglutaminase was used for.. meat glue. Ha! I remember seeing a documentary about commercialized fake fillet mignons, where they marinated meat with tenderizer and then applied the meat glue to roll up the steak into a fillet mignon shape. Now I can’t help to imagine a youtube trend of DIY where people smear meat tenderizer and meat glue on their faces haha. What’s effect on skin anyways? It seems like it would potentially prevent exfoliation, this seems problematic.

[letsalcido]

Coconut oil is not 100% Stearic Acid.

This is basic stoichiometry. Coconut oil is made of triglycerides (3 fatty acids attached to a glycerin). Only about 1-3% of all the fatty acids in coconut oil is stearic acid https://www.sciencedirect.com/topics/neuroscience/coconut-oil

To achieve 6.5% Stearic Acid in your formula would would need to divide the percentage required over the actual concentration of that fatty acid in your oil: (6.5%/0.01 to 6.5%/0.03) so you need between 216% to 650% coconut oil to achieve a final 6.5% stearic acid concentration (not even considering the excess that you would need to add to account for the glycerin byproduct from the oils). Long story short, it’s impossible. If you make soap (just oils and lye and let it cure for water to evaporate) the maximum Sodium Stearate in your soap will be less than 3%.

[letsalcido]

This is an interesting post.

Are you looking to make your own fragrance or purchase finished fragrances?

I think this is a WHOLE different world parallel to cosmetics. Perfumers dedicate full-time to fragrance creation. Each fragrance having 50+ individual compounds, some of which would make us wanna throw up on their own but really enhance other compounds when combined. 

If you just want to purchase a finished fragrance why not work with a perfumer lab? you can create your own signature scent with the help of an expert in the field.

I was doing research about scents myself because I wanted to create blends of essential oils (trying to avoid synthetics) and realized it’s a completely different profession where only practice makes perfect. Chemistry is just a foundation to know which compounds not to mix together or what to avoid for certain applications, but when it comes to the scent itself the technical knowledge does not help. Only years of experience and understanding of all the compounds available.

I think the Fragrance Pyramid is a great resource and http://www.thegoodscentscompany.com/search2.html to get the “tech specs” and good pairings for certain oils and compounds. But it’s all trial and error from there. 

[letsalcido]

@Perry I saw this coming haha I was gonna mention the risk of allergic reactions (a risk that is present at varying degrees with a lot of natural products), but focusing on function only, is it an ingredient that is visibly effective?

I think for small boutique brands, this may be ok as it’s not a product for the mass market. Labeling, and patch testing would be enough, perhaps. For large brands, I understand the need to cover as much market as possible with the least amount of risk.

We use tree nut oils in skin care, knowing that some people have deadly reactions to these. The difference is, perhaps, that people have already identified these allergies and intentionally avoid those ingredients, thus reducing risk? Perhaps also the amount of proteins/allergens that could be in the oil is too small to have a more visible effect on the masses and not just people with severe allergies?

[letsalcido]

Jumping in on this thread because recently I was brainstorming for a face serum and thought of papain.

Some people claim that Papaya seed oil is rich in enzymes (papain). It smelled fishy to me as I would expect that to be in the fruit itself given the known benefits for digestion. A quick search confirmed that papain is water soluble, so chances are the oil has no papain in it. But it could be purchased in a powder.

This enzyme is widely used in meat tenderizer and my understanding is that it is in fact effective for that. I see some claims that it has clarifying and exfoliating effects (in vitro cleaves tight junctions). It also seems that it is the happiest in pH 5-7, which makes it suitable for skin care.

Anything that claims miraculous results I immediately call b.s. on that (eg: adding telomerase or DNAse to a cream and claiming anti-aging effects and reversing mutations caused by UV damage…probably not)

I agree wholeheartedly that most enzymes would have no real effects, but really stable, functional enzymes like papain could actually be beneficial when applied topically? If it works on steak, if may as well work on your cheek, right?

Any thoughts on this?