Formulating a lotion: Fatty Acids and ACNE

In the last post we learnt about the GREASE-FALL, which is “how to distribute the fats in order to obtain a specific kind of cream”.

In this post we are going to go a step forward: we will learn about the fatty acids inside the natural fats (oils or butters). This will help you formulate keeping an eye specially to acne problems.

Choosing Butters and Oils

There are many fatty acids in oils and butters.
The most common ones can be divided in this way:

1) Saturated fatty acids:
– palmitic acid
– stearic acid
– lauric acid

2) Monounsaturated fatty acids
    – palmitoleic acid
    – oleic acid

3) Polyunsaturated fatty acids
    – linoleic acid (more famous as Omega-6)
    – alpha-linolenic acid (more famous as Omega-3)

 Saturated fatty acids are found mostly in butters (the high presence of saturated fatty acids, which are fatty acids that like to sit very close next to each other, makes the butters be solid at room temperature! 😉 ) and they determine the density of an oil.
Saturated fatty acids tend to create deposits and this might happen also on the skin. However, if they are in low percentage, there is no problem in the formulation. 🙂
Stearic Acid, as a lone substance, is also used as a thickener in creams and sometimes soaps; its presence however helps the formation of the unfamous white-trail, therefore do not use too much butters which contain this fatty acid in high percentage or there is a higher risk that your cream will make the white-trail on the skin! 🙂 But don’t worry too much: the quality of the cream, however, won’t change 😉
Lauric Acid has been claimed to have antimicrobial properties.

Now to the more interesting (for our skin) Unsaturated fatty acids, if you know a little bit of Chemistry you will already know that the shape of UNsaturated fatty acids makes it difficult for them to sit close close to each other, like the saturated fatty acids. This is why the oils, which contain mostly Unsaturated fatty acids, are liquid at room temperature 🙂
Within the category of Unsaturated fatty acids we find Monounsaturated (therefore Oleic Acid and Palmitoleic Acid) and Polyunsaturated fatty acids (linoleic and alpha-linolenic acids).

The biggest difference in the oils we use in cosmetics is usually the ratio of saturated, monounsaturated and polyunsaturated fatty acids, so most of the times when an oil is marketed as “something special”, well it often isn’t. For example almond, macadamia, hazelnut oils have a very different cost but their fatty acid composition is quite similar. So before you purchase an oil thinking that it will do something magic, take a moment and look up the fatty acid content of the oil, to be sure that it is not too similar to a much cheaper one!
I know it is tempting to think that the oil of the rarest variety of some extremely exotic plant will finally be your skin-changer… but if you have been sticking around this blog enough, you should know by now that I rarely believe in skin-changing ingredients (there are some effective ones, but the slightly different composition of an oil won’t do the trick) 😉 so do always look up the fatty acid content (and then buy the oil anyway, if you really want to, but at least knowing what you are buying!).

Now, to the correlation between fats and acne:
some studies have checked the sebum production of people with and without acne and apparently people who suffer of acne tend to have a higher percentage of monounsaturated fatty acids compared to the polyunsaturated ones.
Applying more monounsaturated fatty acids (specifically the oleic acid) to the skin might create some problem is this case: it tends to increase the percentage of Ca2+ on skin, which leads to higher keratinization. This can cause even more acne problems.

It is worth considering this disparity in the sebum production when we formulate a cream for somebody who suffers of acne.

The idea is to learn about the fatty acid concentration of our oils and butters to be able to add in our “grease fall” ingredients with a higher concentration  of polyunsaturated compared to monounsaturated ones.

A practical example: I use very low percentage of butters (0.5-1%, but even this small amount is needed for the consistency of the cream) and then, when I have to pick the oils, I pick them with different densities but I make sure that they are low in Oleic and Palmitoleic Acids, while they are rich in Linoleic and Alpha-Linolenic Acids. This is what I have done and so far and I have had good results 🙂

Online you can very easily find data about even the most exotic oils: both on their density, spreading ability and content of fatty acids.
Here I will just sum up very briefly which oils have relative higher content of linoleic and alpha-linoleic acids:
Black currant oil
Borage oil
Cucumber oil
Grape seed oil
Hemp oil
Primrose oil
Raspberry oil
Passion fruit oil
Safflower oil
Sunflower oil – this is the cheapest option
Soy oil

There are also a few butters that, compared to other butters, seem to have a slightly lower content of oleic acid, for example Murumuru butter, Coconut oil and Tucuma butter.
However butters don’t have high content of polyunsaturated fatty acids (or they wouldn’t be butters anymore, as I explained before).

Hope this was helpful! 🙂
I am sure there would be more and more things to tell about fatty acids but maybe in a future post.

Have a great day! 😉

Formulating a lotion: Choosing the fats – THEORY pt.5

[Actually the title of this post should be CHOOSING THE FATS / THE SECRET OF THE GREASE-FALL!] 🙂

You have learnt which percentage of fats your cream should approximately have, according to what kind of lotion you want to create; now it is time to learn how to distribute the fats within the percentage you have chosen.

The choice of the fats and their percentage in the formula is of big importance because mostly from them depends the touch of the cream: the more you know about them, the better you will be able to formulate. But let me explain how 😉

I will talk firstly about the OILS, and later on I will briefly talk about butters and waxes.
When talking about oils (but this goes also for other fats) you do not want to look much at their so-called “miraculous” properties (I won’t repeat this often enough!); what you want to look at, instead, are their technical qualities:
– density,
– spreading ability,
– feeling on the skin/absorbing ability of the skin.

– fatty acids composition.

[Note: on the internet you can find slightly different data from what I am reporting here: mine is my personal sum up and what I believe to be the most correct data. You are free to make a research on your own and give more value to different data you find 🙂 ]

Density – tells us, surprise surprise, how dense an oil is. For example castor oil (dens. 0.96) is one of the most dense oils, while jojoba oil (to be very precise it is not actually an oil, it is an ester… but let’s think of it as an oil for now 🙂 ) is one of the least dense (dens. 0.869).
Spreading Ability – this concerns how the oils spread on the skin. Don’t be mistaken however thinking that the spreading ability will tell you which oil has a light impact on the skin: an oil can spread very lightly and, at the same time, give a greasy touch. How? Well, the spreading ability tells you how the oil, when spreading it on the skin, is going to feel like: if an oil is very dense it will feel like you hardly manage to spread it, a medium oil will spread quite nicely and leave quite a good feeling in the end, while a light oil will most likely spread very fast and, at some point, you will feel as if it actually disappeared (don’t be mistaken by this: very light oils are very likely to, after 5 or 10 minutes, appear again on your skin leaving you with a greasy face 🙂 ). Now I will give you some data examples: wheat germ oil is DD (very dense) which means it doesn’t spread much but it is quite a “thick” oil; peanut oil is classified as D (dense), meaning that it doesn’t spread very easily; olive oil is classified MD (medium density); Almond oil is classified as M (medium spreading ability); Borage oil is Fl-M (fluid-medium: spreads a little bit better than a medium oil); primrose oil, instead, is classified as Fl (light-fluid) and sunflower oil, eventually, is classified L (light).
Absorbing ability on the skin – As I was just pointing out, some oils “show back” on the skin even if in the beginning they spread so well that you thought they had disappeared 🙂 what we really need to know, in terms of what is going to show on the skin, is how do these oil absorb on the skin. I will bring some examples again: wheat germ oil – greasy; borage oil – a little greasy; macadamia nut oil – oily feeling; almond oil – oily feeling; olive oil – oily feeling; argan oil – medium; jojoba oil – good absorption; sunflower oil – good absorption.
[These factors can be said also about synthetic oils.]

Fatty Acid Composition deserves a bigger discourse and it is not too important for the explanation of the GREASE-FALL, so it has its separate post.

Now finally… THE GREASE-FALL   🙂

You have learnt that oils and butters are different in composition and in how they behave on the skin. But how to use this information when we have to formulate?
Well, imagine you have a rather oily face and you want to create a cream for it. You want a light cream, easy to spread and absorb… and you don’t want it to make your skin greasy at all. If you didn’t read what I just said about the spreading ability I am sure you would think “I will make a cream with light density oils!”.
Well… and that would be SO WRONG! 🙂 The cream would spread even too easily, it would feel fresh in the beginning but after 5 minutes you would be all oily once again.
And imagine you have a very dry skin and you would like to have a very rich cream: probably you are thinking to make it only with fats like, let’s say, shea butter… am I wrong? It’s a rich butter, it has high vitamin E content… nothing could be better than that.
Well… WRONG AGAIN 🙂 you would get a cream which is not nice to spread, leaves your skin white unless you try to spread it nicely and you wouldn’t feel hydrated as you wish.
So what is going wrong?
Well, it’s very simple said: you are not formulating a GREASE-FALL, you are just adding oils randomly! 😀

So what is this bloody GREASE-FALL RULE:
whenever you start formulating a cream and you are clear which purpose you want it to have, you have to balance the different kinds of fats! Every cream, to be a good cream, need all the kinds of fats!
So how to differentiate a light cream from a thick cream for dry skin?
This is the magic of the grease-fall rule. 🙂 The idea of using shea butter for dry skin is not bad, but you will have to add also all the other densities; let me show you an example:
let’s say our dry-skin cream will have a percentage of 12% fats, you can organize the fats like this:
1% beeswax (for example, very high in density and low spreading ability. Gives richness to the cream. Never exceed with waxes though)
6% shea butter (you could also do 2% mango butter and 4% shea butter… the point is to keep butters at 6% because they are more emollient than most oils)
3% argan oil (medium to rich oil)
1% borage oil (medium)
1% jojoba oil (very light)
This is just an example which I “invented” exactly now and I am sure I could do better but, once you get the grip of it, you will love changing and experimenting on your own, so don’t give too much importance to this; it is just to give you an idea of how to create a balanced grease-fall: you put the highest amount of what you need and then, like in a rough gaussian distribution, you add everything else in minor amount.
So here is an example of a grease-fall for oily skin:
let’s say we will make a cream of 5% fats (with 5% it is not easy to make a good grease-fall and it is also quite hard to tell the difference in a cream 🙂 but we try to be professional no matter what 🙂 ok? )
2% jojoba oil (or, if you want to use synthetic oils, there are some which are much lighter than jojoba oil: for example dicaprylyl ether. Always bear in mind that even if they are very light, if you use too much, they will show up again on the skin)
1.5% sunflower oil (light)
1% black currant oil (medium-light)
0.5% shea butter
As you can see the shea butter is extremely low in % but still it will help the cream to be more balanced in the end 🙂

I hope I managed to be clear enough about this matter because it is an important one! 🙂
Let me know if you have any questions! 🙂