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Polar Value of Oils and Other Lipids
Hi,
Are there books or resources on polar values of oils and other lipids (other than the 2 articles on free patent) please?
Following my last post on failed olivem 900 emulsions, I am still not able to achieve a stable w/o emulsion and having read this olivem brief, I think I might find some answers in polarity..
Thank you.
https://chemistscorner.com/cosmeticsciencetalk/uploads/editor/c9/3yc4604eyfho.pdf
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22 Replies
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I agree polarity is important when you formulate w/o. You were using vegetable oils as I remember and they all are pretty polar. I couldn’t find a comprehensive list of polarities either, however as a general rule most vegetable oils are polar, silicone and hydrocarbons are non-polar. Esters can be all types. If you try to keep formula ‘natural’, squalane is plant derived hydrocarbon. I usually use isododecane, isopropyl myristate (both non-polar) silicones and add medium polarity esters (coco caprylate, octyl palmitate, cetearyl isonononoate etc) in w/o. You might want to try coco caprylate and squalane.
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@ngarayeva001 thank you for replying again
yes from what I gathered from the olivem brief, the larger part of oil phase consists of squalane. seems like sorbitan olivate tolerates rather little polar oils unfortunately and keeping it “natural” really takes out most of the options..nonetheless, I’ll keep trying. I hate being stumped lol
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@africanbug, I don’t know what limitations you have when it comes to materials but it’s relatively easy to find decent w/o emulsifiers that can be classified as natural. Can you change emulsifier or you must use olivem? You can try a combo of polyglyceryl-2 DPHS and isolan GPS and squalane plus coco caprylate as your oils. Need to check my formulas but I remember this combination works pretty well. It can even be processed cold with zinc stearate as a stabiliser.
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@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/alcoholsEsters (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!
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Oil (CTFA Name) Polarity Index [mN/m] Isoparaffin (C12-C14) 53.0 Squalan ® 46.2 Hydrogenated
polyisobutene (Luvitol Lite ®)44.7 Isohexadecane
(ARLAMOL ® ND)43.8 Isohexadecane 43.8 Mineral oil
(Paraffin oil perliquidum)43.7 Mineral oil 43.7 Isoeicosane 41.9 Dioctylcyclohexane 39.0 Mineral oil
(Paraffin oil subliquidum)38.3 Dicaprylyl
carbonate31.7 Dicaprylyl ether 30.9 Dihexyl carbonate 30.9 Cetystearyl
octanoate28.6 Passiflora
Incarnata Oil (Cegesoft ® PFO)27.2 Oleyl Erucate
(Cetiol J600 ®)27.1 Dimethicone
(silicon oil 20 ct)26.6 Jojoba oil Gold 26.2 Myritol ® 312 25.3 Isopropyl palmitate 25.2 Octyldodecanol 24.8 Dioctyl adipate
(ARLAMOL ® DOA)24.5 Isopropyl myristate 24.2 Octyl palmitate
(2-ethylhexyl palmitate)23.1 Hexamethyldisiloxane 22.7 Macadamia nut oil 22.1 Rapeseed oil 21.9 Isopropyl stearate 21.9 Isopropyl stearate 21.9 Caprylic/capric
triglycerides21.3 Isopropyl
isostearate21.2 Jojoba oil 20.8 Cyclomethicone
(ARLAMOL ® D4)20.6 Groundnut oil 20.5 Almond oil 20.3 Sunflower oil 19.3 Decyl oleate 18.7 Avocado oil 18.3 Olive oil 16.9 Dibutyl adipate 14.3 Castor oil 13.7 Calendula oil 11.1 Water 10.2 http://www.freepatentsonline.com/y2004/0258654.html
I don’t know how accurate is this list (c/c triglycerides is more polar than sunflower oil, based on my experience), but I would rely on Tony Olenick’s point
https://www.cosmeticsandtoiletries.com/research/chemistry/17390254.html“Typical polar oils are fatty alcohols, esters and triglycerides”. Vegetable oils are mostly triglycerides, which means they should be polar.
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https://www.happi.com/issues/2014-11-02/view_formulator-forum/how-to-select-emollients-for-stable-emulsions/
useful article on the stability of emulsions. -
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).
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Cosmetics and chemistry/science will never be good friends unless the former can abuse the latter to ‘proof’ benefits/claims
.Most of cosmetic ‘science’ is highly empirical… -
Not the most scientific way but for the lack of something better: polysorbate 80 has high HLB and very “water-like”. Obviously it doesn’t want to mix with oils and sinks in the bottom of the beaker (I was making oil to emulsion makeup remover). However, there are some oils with which it forms a clear solution (even after many months). I couldn’t find a comprehensive table of polarities but I noticed in BASFs emollient tables that the oils that mix with polysorbate 80 are highlighted as “high polarity”. Those are (from my experiments) c/c triglycerides, octyldodecanol and c12-15 alkyl benzoate. Also, my very first w/o experiments were separating although I did everything else right (I was using alkyl benzoate and octyldodecanol). They stopped separating when I switched to isododecane, IPM and some other emollients that were classified as esters with medium polarity by BASFs table.
http://www.eurotradingonline.it/wp-content/uploads/2014/12/Emollient-spreadsheet-.pdf
I checked all the cosmetic chemistry books that I have but there are not polarity tables there. All you get is “non-polar oils form more stable emulsions” -
letsalcido said: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.
that I can do
thank you -
ngarayeva001 said:@africanbug, I don’t know what limitations you have when it comes to materials but it’s relatively easy to find decent w/o emulsifiers that can be classified as natural. Can you change emulsifier or you must use olivem? You can try a combo of polyglyceryl-2 DPHS and isolan GPS and squalane plus coco caprylate as your oils. Need to check my formulas but I remember this combination works pretty well. It can even be processed cold with zinc stearate as a stabiliser.
I can change emulsifiers as long as it is natural. it is just that I have olivem900 on hand and with the current covid lockdown, it is not as easy to buy and ship materials! I looked at my stocks and I have about 20ml of squalane left, not enough to attempt an emulsion. Having had 20 failed formulations with Olivem900, I am pretty tired of all the washing lol so I will take your recommendations and try to find the ingredients you mentioned above. I will post an update here when I make the emulsions. Thank you so very much @ngarayeva001 ❤️
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@ngarayeva001
I shun chemistry and don’t have the brain for it, you might find these 2 articles interesting though.. -
@africanbug I completely forgot about the Abbott book. Started reading it few months ago but ‘lost’ it. Thanks for the reminder. That book is pure gold!
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Pharma said:@africanbug I completely forgot about the Abbott book. Started reading it few months ago but ‘lost’ it. Thanks for the reminder. That book is pure gold!
@Pharma
it is very informative but so much to wade through! -
ngarayeva001 said:You can try a combo of polyglyceryl-2 DPHS and isolan GPS and squalane plus coco caprylate as your oils.
@ngarayeva001
I have checked most of the usual suppliers like FSS, MakingCosmetics etc but can’t find anyone that carries Isolan GPS, is it only available B2B suppliers? -
Last time I checked, glamourcosmetics.it has Isolan GPS.
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yes just saw it but unfortunately they don’t ship to Singapore.. at least not currently
has anyone tried using Polyglyceryl-2 Dipolyhydroxystearate with Polyglyceryl-3 Diisostearate?
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Have a look what Trulux have. It’s Australian supplier. They have very advanced ingredients but prices are a bit outrageous. I know for sure they have polyglyceryl-2 DPHS
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ngarayeva001 said:Have a look what Trulux have. It’s Australian supplier. They have very advanced ingredients but prices are a bit outrageous. I know for sure they have polyglyceryl-2 DPHS
yes I found the polyglyceryl-2 DPHS there. the prices are rather outrageous but they carry some harder to find ingredients. I buy from them products that I can’t find elsewhere
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Oh they have Dow Corning’s formulation aid 5225 water in silicone emulsifier. It isn’t sold anywhere else and it’s fantastic for foundations. They also have my most favorite w/o PEG-30 Dypolyxydroxystearate which creates light and fluffy HIPEs that have benefits of w/o but feel like o/w. There’s also Ez4U by Lubrizol, a polymeric emulsifiers that can stabilise impressive amount of oil and creates gel at just 0.2%. Those 3 are the reason I order from Trulux. They have Abil EM 90 w/si emulsifier (I have love hate relationship with it) but that one is also sold by glamourcosmetics.
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