There is nothing (much) new under the sun.
Your intellectual property is valuable and important but probably not for the reasons you think it is.
Many people get upset when they come out with a new product range only to find someone else do the same a few months later – sometimes using similar packaging and ingredients. As maddening as that can be it is really important to separate the copy cat from those competitors who just happen to have similar taste to you, use the same suppliers or watch/ read the same stuff.
Straight out copying is bad. I’ve come across people so brazen that they will call up and ask a brand where they got their ingredients and packaging from before going out and re-doing it themselves.
If your brand is on the receiving end of this kind of attention it is absolutely OK so say ‘no, that information is not for sharing’ although, depending on the size of the supply market it may not take too long for them to find out anyway. That’s just the way it is. However, if you feel you are seriously being stalked then replicated that is worth getting legal advise on. There’s a line of decency that should not be crossed.
But back to the similar and annoying type of ‘copying’.
From where I sit I see enquiries for products come in waves – micellar water, charcoal teeth whiteners, papaw balm, beard oils, coffee scrubs…..
Things like the above become popular because they capture or tend to a fashion of the moment. Coffee scrub is actually a great example. There were tonnes of coffee scrub brands about before one particular brand make them ultra-sexy on Instagram. The ‘original’ coffee scrubs (of which there were hundreds) were probably (and rightly) annoyed to find this newbie selling out by the bucket load while theirs was still plodding away. This can and does happen a lot in an industry that is predominantly driven by fashion and lifestyle.
And that’s where your brand IP comes in.
Your formulation and ingredient choices are only one part of that – it’s the part I spend much of my time in my business creating/ working on but even so I’ll readily admit it’s not the be-all-and-end-all of a brands IP.
Brand value encompasses all of these things and it is because of this list that we shouldn’t stress out when a ‘competitor’ cottons on to the fact that we are using native pea juice in our serum now (or whatever happens to be the next big thing).
- Our recipe or formulation.
- Manufacturing instructions.
- Ingredient supplier.
- Packaging supplier and specs.
- Marketing strategy and how we implement it.
- Brand look and feel.
- Brand dynamic – how it interacts, the language we use, the platforms we inhabit.
- Business reputation including time in business / business standing.
- Personality of staff/ contact points.
- Accessibility of product – can I buy it, how long does it take to get to me.
- How ‘good’ the product is.
- Customer relations.
- Shopping experience.
- Recommendations/ Endorsements/ Testimonials.
- Functionality – is the product usable? Does it last? Does it do what it says it will?
Have I missed anything?
The long and short of it is it is very likely that other people will use the same packaging as you, similar ingredients and even share the same suppliers as you (especially here in Australia where choice is limited). That doesn’t necessarily mean they are watching your every move and nor does it mean your customers will be too.
The best brands (in terms of how satisfied they are with their business and how happy their customers are ) that I work with are the brands that focus all of their attention on what they are doing and what their customers want and only occasionally look out to see what’s going on in other places. The most unhappy brands I come across have that ratio flipped right around and feel like everyone is steeling their ideas. Some brand owners are so scared of copy cats they won’t even open up to have other people help them – I’ve certainly felt that before.
If you are in any doubt as to whether you are being blatantly ripped off do get some professional advise as the negative focus will not help your business grow but if you are just sharing a vibe with others that’s pretty normal. In fact, as a brand you can take some comfort from the fact that other people are doing/ using the same stuff as you – you obviously have popular taste!
And for those cases where you want to put very firm boundaries in place to protect your investment see an Intellectual Property Lawyer and invest ahead of time.
Good luck guys x
This question came up last week and for as usual I thought about it for a moment then said ‘yes of course, I have bought it – dispersed in soya oil but Aloe Oil never the less’ but then I thought on a bit further.
Here’s one of my pots of Aloe. My plant has had so many babies I’ve got Aloe all over the house which is nice but I’m a bit worried that I’ll run out of places to put the babies and I wouldn’t want that!
So what was the Aloe Oil I bought?
On further investigation I discovered that the Aloe Oil that I’d used in the past was soya bean oil (which I already knew) infused with Aloe Vera Juice Powder. Interesting but not quite what I thought Aloe Oil would be.
Where is the oil in Aloe?
Being a succulent herb Aloe is more water than oil but it does still contain some oily components – fatty acids. These are actually bound up in the watery juice part which does shine some light on why the Aloe Oil I purchased was an infusion of the juice.
Before we get too excited about Aloe being a great source of fats it looks like the fatty acid component of Aloe is less than 1% of the total chemistry of the plant – that’s pretty tiny and is probably why people don’t tend to sell straight out Aloe Oil. Too expensive to produce and not worth it! (Chemical constitution, health benefits and side effects of Aloe vera. Indian Journal of Research. Dr Sanjay Sharma. 2015)
Aloe fatty acids are typically Lauric (2%+-), Myristic (3%+-), Palmitic (40% +-), Stearic (15%+-), Oleic (7%+-), Linoleic (12%+-) and Linolenic (18%+-) (Effect of Heat Stress on Fatty Acids Profiles of Aloe vera and Bryophyllum pinnatum Leaves.Mushtaq Ahmad, Hasnain 1 2 Nangyal, Sikandar 3Khan Sherwani,Ziaul Islam and 1Safdar Hussain Shah. World Applied Sciences Journal 28 2013)
The first paper mentioned here investigates what happens to the fatty acids in Aloe when the plant is heat stressed. It shows the level of saturated fats rises in times of high heat while the unsaturated fat levels fall. The writer hypothesizes that the saturated fats could be protecting the plant from heat stress.
The second paper mentions some other fatty constituents of the Aloe including Archidonic Acid and sterols (such as cholesterol) – both of these fatty materials are naturally found as components of cell membranes and could contribute to Aloes healing power – but keep in mind they will be present in tiny proportions.
So what should I look out for when I purchase Aloe Oil next time?
It is most likely the Aloe Oil will be from the powdered gel and will be dispersed in a carrier oil. The carrier oil could be anything so check this out and make sure it is suitable for your application (organic/ long shelf-life/ nut free/ sustainable/ cost-effective etc). The blend may or may not be supplied with Vitamin E added. Natural vitamin E is an antioxidant and may be needed to preserve the ‘freshness’ of the carrier oil.
It is possible (though less likely) that the Aloe Oil will be 100% Aloe, extracted from the plant. I would expect this to be quite expensive and would also expect it to have been produced using a solvent of some kind to help improve the yield. That solvent could (theoretically) be Carbon Dioxide (Co2 extraction) or may be hexane or similar. Do check that out so you have confidence the product matches your product philosophy.
So that’s it really.
Aloe Oil is a thing but usually it will be an oil dispersion rather than a pure oil.
Sometimes things don’t always work out as you expect. This is a story about that.
One of my favourite natural preservatives at the moment is a blend of glycerine with Sodium Levuninate and Sodium Anisate. I love it because it is clear, colourless, odourless and high performing. I’ve put a few formulations through Preservative Efficacy Testing with this preservative and had them pass – creams, spritz, cleansers (gel and emulsion based) and masks – so my faith in this little beauty is grounded in science which re-assures me.
So what’s odd then?
Well it turns out that I forgot to adjust the pH down on one of the products I just got results back for so the resting pH was 6.15 instead of the pH 5 that I wanted it to be. I usually adjust the pH of my formulations containing this ingredient because the manufacturer says that the product works best in acidic conditions. It’s not that pH 6.15 isn’t acidic – anything less than pH 7 is acidic – more that the pKa value of Levulinic Acid is 4.61 so at pH 6.15 it would be almost 100% salt, not acid and I’ve been told it is the acid that has the preservative action rather than the salt.
Aside disk of pKa.
All of the acids we use in cosmetic science are ‘weak’ acids and as such exist in a mixture of their salt and their acid form. The point at which both acid and salt forms are in balance is acids pKa value. Above the pKa (more alkali) the acid will exist mainly as the salt and below, mainly as the acid. At the pKa it’s 50:50. A change in pH of 1 jumps the ratio up very quickly, so that around 90% of the ingredient is in its acid or salt form depending on if it jumps up or down. So for Levulinic Acid a pH of 5.61 means 90% Salt whereas a pH of 3.61 is 90% Acid.
The PKa value is a constant and each acid has one, some have more (such as citric acid).
And back to the oddness of what’s going on in my formula
But then again, the manufacturer does say that the Sodium Levulinate/ Levulinic Acid can work between pH 4-6 while the p-Anisic Acid/ Sodium Anisate work between pH 4-6.5.
So maybe pushing a pH of around 6 isn’t so bad after all.
Especially given that my pH 6.15 product passed PET.
On another note some stability testing I’ve been doing on a formula using this preservative have also showed the pH to rise from 6.15 – 6.45 over 16 weeks in the oven (equivalent to around 15 months real-time) and that has been playing on my mind – are these products now un-preserved? I need to get them micro-tested to check….
So I had a look into the science and found that Sodium Levulinate is commonly used as a meat preservative. In this patent here you see the pH of the samples tested are between 5.8 and 6.23 and the preservative worked well in all cases in spite of the fact that even at pH 5.8 we have only around 55% as Levulinic Acid. This paper talks about Sodium Levulinate being the preservative rather than levulinic acid and this paper found that Levulinic Acid produced disappointing results when compared with Lactic or Acetic acid for meat washing – a bit of a web search on google scholar confirmed my suspicions that it is the Sodium Levulinate that is used more than the Levulinic acid.
There is another reason why I’m insanely interested in this is solubility.
At pH below 5.5 the above blend does indeed switch from its salts to its acids, you can see that visibly as while the salts have good water solubility the acids do not. As the pH reduces the preservative starts to form little white crystals if it is in a water-dominant formula, this wouldn’t be such a problem in an emulsion as the acids would usually find something else to dissolve or disperse into but if your product is predominantly water there will be trouble!
From what I’ve looked at, got results on (PET) and seen with my own eyes a pH of 6 in a water-dominant product is probably fine and will allow for the use of this preservative without fear of the preservative coming out of solution. Lower the pH and you will have a problem, not necessarily with preservation but with product clarity.
But what about the rise in pH over time?
I suspect that what is happening, and especially in the presence of a catalyst such as heat, is that there is a shift towards the salt formation over the acid form. I suspect this because the starting pH of the preservative is between 7-8.5 (mine was pH 8 @ 18C) and the ability of the reaction to go both ways. Whether this impacts the long-term micro stability of the product is yet to be seen (or measured). The only thing I can say is there must be a reason the manufacturer gives a cut-off pH of 6.5. But what is I wonder?
Micro contamination typically reduces the pH of the product as the microbes produce CO2 as a bi-product of respiration. This CO2 acidifies the environment which could, at least in theory, push the equilibrium back towards the acid form (for the preservative) and therefore more within the target range of action. That said, one wouldn’t want to wait for micro contamination to bring the pH down, a buffer solution would be a better idea!
Overall I think there is enough evidence to say that the salt form of both actives are effective preservatives and that the pKa values of these ingredients is, for whatever reason of minor importance for this application. Ignoring the pKa values is something I’m fairly happy to do but even though it makes no logical sense given what I’ve said above to stick to the manufacturers guidelines of max pH 6.5 I am lacking the real-time evidence at this point to back that up. What I would say though is that in a cream formulation a very water-soluble preservative would be un-desirable as it would leave the interface between the oil and water vulnerable. So, it would make logical sense for the pH to be lower to reduce the water solubility (by increasing the percentage of the preservative that is in the acid form) and thus keep the preservative at the interface. This is irrelevant in a water-only or water-dominant formulation where the contamination risk is predominantly in the water phase.
At low pH (below 5.5) the salts in this blend change to their acidic form. The acids have low water solubility as we can see here with the precipitate that has formed. This is a problem in a water-dominant formula but is less so in an emulsion as the acids can better disperse in a multi-phase system.
So yet again something that I took for granted as being simple has potentially turned out to be quite different indeed.
I might well try the preservative at pH 8.5 in a water-dominant formula to test this theory (I know that one sample doesn’t constitute a good scientific trial but it’s a start). I could also try a cream formula at pH 7 to see how that fairs (my other creams have been at pH 4.5 and pH 5.2 and passed).
But for now that’s that.
Thinking about stuff is always exciting and very interesting wouldn’t you agree?
There is so much advice available on the internet these days (oh god, I sound like someones grandma) and not all of it is good. In fact, it is safe to say that the vast majority of it is bull crapola really, not because it is wrong, but because it isn’t really likely, possible, practical or applicable. When I’m talking like this I’m focusing on my pet subject, chemistry.
As far as I know chemistry still isn’t drawing in the crowds like other degrees seem to. Law and Medicine remain eternally popular but the humble old chemistry is just a bit too hard, too abstract and too……. full of chemicals I guess. So basically we live in a technically advanced world but one in which very few people know what the hell is going on. Interesting turn of events that.
To illustrate this I had a meeting today about a new cosmetic ingredient that is essentially a feat of chemical genius in spite of it being totally and utterly natural. In fact one could use this ingredient to make nature greater! Playing God or just being smart? I’ll take both and dunk my biscuit in it.
The trouble is that in a world that is almost chemically illiterate ingredient ideas like the above are poorly understood, supported and invested in until they can quite literally spell out their advantage in the kind of plain English that a 5-year-old would grasp which is a shame as there is so much more beauty, enjoyment and satisfaction to be had in life once we understand the detail.
But anyway, this type of situation plays out all over the net every day. In the past year or so I’ve noticed a marked increase in people who come along to the help desk I man overwhelmed and deeply confused after receiving (or reading) so many conflicting reports of what is what on the internet. This is not surprising, I’m sure I’ve blogged about this before but I do want to say it again.
Cosmetic chemistry is an applied chemistry, the devil is in the detail, there is usually more than one answer to a question and not everything that is possible is probable.
I find it relatively easy to discern between the ‘do’s’ and the ‘parrots’ and I think you should be in on this because it saves time:
- The ‘do’s’ will always be happy to say ‘you know what, I don’t really know but I think I know how we might be able to find out’ and no, they don’t mean they will ‘google’ it.
- They understand chemistry AND formulating enough (including how the product is to be manufactured) to be able to break down with you the reasons why certain ingredients will work well together and why others might not.
- They will give you confidence to try to explain what to look out for when (if) things have gone wrong.
- They ask you (and this is VERY important) LOTS of questions about what you are doing BEFORE they jump in with an answer.
- They pre-empt your ‘rookie’ questions and answer them pro-actively to save you the embarrassment.
- They tend not to give blanket ‘just use x’ type answers or use them with a caveat knowing that ‘x’ isn’t the answer for everything.
- They feel happy/ comfortable in sharing how they know what they know, where they went wrong and how they recovered their bad situation.
- They either have evidence to back up their suggestions based on their experimentation or can point you to real third-party science data that will do the same.
- They ask you questions and encourage your input into solving your own problems – teaching by empowerment.
On the other had there are the Parrots.
Parrots generally invest much of their time outside of the lab, listening in to what everyone else is saying before parroting it back louder and stronger so as to sound as knowledgable and authoritarian as possible. Questions you ask are given straight, direct no-if’s, no but’s answers ‘this is what you need’ type of thing and coming back with more questions quickly becomes tedious to them as it means they have to take that question on notice while frantically running around looking for the answer usually without ever setting foot in the lab.
So is what I’m saying nothing more than lab snobbery? ‘Im a chemist’ stuck-up-ed-ness?
No, you don’t need a chemistry degree to do this.
What I’m talking about is lab-reality.
We all know the scenario – we were all going to be perfect drivers that never changed lanes without indicating or daydreamed for a few too many seconds before catching up with the traffic jam BEFORE we got behind the wheel after a long and stressful day’s work…
We were all going to be the perfect pet/ human parent feeding only organic hand-made nourishment to our beloveds BEFORE we got ourselves a family.
We all knew how to make the perfect serum/ shampoo/ moisturiser/ sugar scrub BEFORE we tried to do it for ourselves and make a commercial go of it….
Life, it doesn’t always ‘go’ by the book.
And chemistry is no different.
I enjoy the fact that cosmetic chemistry has been accessible for so many more people and that it is easier than ever (in some respects ) to start-up your own brand – at least here in Australia. But what I do worry about is the growing reality that many people seem to be fumbling around in the dark looking for guidance. Sometimes it’s best to just turn the bloody light on.
Get into the lab as often as you can as there really is no better teacher than real, practical hands-on experience.
I graduated as a chemist a while ago now and have been working professionally in the beauty industry for over 18 years – a time that has, on the one hand gone in the blink of an eye but on the other feels like an eternity.
Anyway, I just wanted to share with you the main thing that keeps me getting up and doing this day after day, week after week, year after year. It is simple, I LOVE it.
The ‘it’ I’m talking about is chemistry, wearable chemistry.
I’m not the kind of girl who raves about a new brand of moisturiser or who wears all the new shades of lipstick or blush but I am the kind of girl who gets very excited about HOW all of this comes into being.
My whole professional world revolves around a joy of chemistry, of understanding what happens when this goes with that, of how it feels, spreads, lasts and ages. I love the detail and never tire of learning more.
Over the last month I’ve been building a new adventure to go along with what I’m doing here. I don’t know how it is going to turn out yet or when it will happen so I’ll leave you hanging on that but what it has done is opened my eyes to the fact that for many science just isn’t fun anymore. Since I started in the beauty industry there has been a feeling that ‘chemical’ is a dirty word and while I’ve never took that sentiment to heart I have to say I got on with it (that mentality) because that’s what was ‘in’. However, I’m becoming increasingly angry at how little interest and understanding exists around chemistry, its beauty and functionality. I make it my mission every day to try to put the fun, beauty and love back into this beautifully elegant science.
So my thinking and mental travelling has taken me back to somewhere around the 1930s when Art Deco was the fashion, an art inspired by brave geometry, new lines, science, the future, inventiveness and bold discoveries. I have gone back to a time when every little boy and girl got a chemistry set for christmas (well, not every one but you know what I mean), when making stuff didn’t involve fear, when great strides were being made in our understanding of the world and our place in it. While there are aspects of the ‘chemical revolution’ that have had less than exciting ramifications it is the energy and ‘can do’ mindset that I’m channeling, the optimism and fun that was to be had.
And on that note I have started to re-organise my office, inspired by the labs of the early part of the 20th century in the hope that I too can channel that enthusiasm and bring the joy back to chemistry.
I know there are lots of different types of emulsifiers but how do different emulsifiers make my emulsion feel?
After all the reading in my last article: The Secret Life Of The Emulsifier I feel it is time to bring things back to the lab again as we try out a very simple yet effective experiment to demonstrate how one might answer that very important question ‘This chemistry is all well and good but how do these emulsifiers FEEL?’
I developed a very simple formula based on a common non-ionic emulsifier – Cetearyl Alcohol and Cetearyl Glucoside. This formula was then replicated with different emulsifiers, one from each different class (except silicone). The products were evaluated by an expert panel of five people as well as having their viscosity checked before being evaluated under the microscope. The idea of this base formula was for it to be stable and easy, I wasn’t too bothered about anything else at that stage.
The formula and feedback is not presented to help sway a decision towards or away from a particular type of emulsifier, merely it is to illustrate a point, that the emulsifier can impact everything from viscosity to feel, efficacy to stability. It also demonstrates the importance of optimizing the whole formula so as to get the most out of the emulsifier of choice. Plus there is always room for pairing up on technologies or trying something new!
So the only difference between these formulations is the emulsifier except for the cationic version which was incompatible with the thickener Acacia and Xanthan gum blend. In the cationic I used a cationic guar at the same level.
Formula 1: Cationic (Brassicyl Isoleucinate Esylate (and) Brassica Glycerides (and) Brassica Alcohol)
Formula 2: Anionic (Potassium Cetyl Phosphate)
Formula 3: Non-Ionic (Cetearyl Alcohol, Cetearyl Glucoside
Formula 4: Mixed Anionic/ NonIonic. (Glyceryl Stearate (and) Cetearyl Alcohol (and) Sodium Stearoyl Lactylate)
Formula 5: Non-Ionic Synthetic (Cetearyl Alcohol, Ceteareth-20)
Formula 6: Polymeric (Acrylates/C10-30 Alkyl Acrylate Crosspolymer)
Formula 7: Liquid Crystal Emulsifier (Cetearyl Olivate, Sorbitan Olivate).
Formula 8: HLB balance (Sorbitan Monooleate, PET-20 Sorbitan Monostearate)
Viscosity @ 3.0 Spindle
Thin, high spreading, slightly tacky to touch at first drying to powdery.
Silky, takes a while to absorb, feels substantive after drying.
Easy to rub in
Very thick and creamy, light after feel
Ultra-light, quick break and high spreading. Tacky on drying.
Rich waxy texture, slow spreading
Very light and spreadable
Base formulation used.
|A. Water Phase||Deionised Water||71.95||143.9||Solvent|
|Acacia and Xanthan Gum||0.4||0.8||Thickener/ Stabiliser|
|B. Oil Phase||Jojoba Oil||8||16||Emollient|
|Shea Butter||8||16||Barrier Protection|
|Emulsifier of choice||3||6||Emulsifier|
|Cetearyl Alcohol||1.25||2.5||Emulsion Stabiliser|
|C. Finishing Touches||Natural Vitamin E||0.5||1||Antioxidant|
|Preservative (Phenoxyethanol, Ethylhexylglycerin)||1||2||Broad Spectrum Preservative|
As expected the polymeric emulsifier produced the largest dispersed phase droplets.
Top: Formula 6: Polymeric (Acrylates/C10-30 Alkyl Acrylate Crosspolymer)
Bottom: Formula 5: Non-Ionic Synthetic (Cetearyl Alcohol, Ceteareth-20)
The Cationic emulsifier Vs Anionic Emulsifier.
4 weeks in 40C oven pass at time of going to press.
There really is a lot to take in when developing complex cosmetic formulations including the ionic strength and polarity of your water phase, your marketing departments wishes, the viscosity and feel you are trying to achieve and the packaging you hope to sell in. That said, today we are lucky enough to have at our finger tips a wide range of different ‘drop-in-and-go’ technology to help us balance creativity with tight deadlines. My only hope is that we remain engaged and inspired by the chemistry that underpins this convenience so we can keep on innovating for centuries to come.
These days, one could be forgiven for thinking that creating an emulsion is child’s play. We have available at our fingertips tens, if not hundreds of self-emulsifying pre-blends that require no fiddly HLB calculations or secondary stabilisers. Well, that’s the theory anyway. You see, when you start making skincare formulations the chances are you will mostly be working on relatively simple oil-in-water concepts with stable, predictable actives and a simple vegetable-oil derived dispersed phases. Indeed, it is even possible to make some pretty exciting anti-ageing, brightening or cleansing formulations without hitting any hurdles all of which add to the general feeling of accomplishment for the freshly graduated chemist. But it doesn’t take long for that initial bravado and ‘beginners luck’ to fade and when it does it pays to have a few tricks up your sleeve.
I want to forget for a moment that we have these self-emulsifying blends and concentrate on working from first principals, not so we can do lots of math and get lost on somewhat superfluous detail but so we can design our creams from the ground up, so that we can make anything and so that it has at least a fighting chance of working out for us!
So let’s start by asking ourselves a few questions, what do you need to consider when selecting an emulsifier?
The way I see it there are four main categories that deserve consideration:
- Marketing/ Product Positioning.
- Physical Character
As Cosmetic Chemistry is an applied science I feel it is appropriate to start with the marketing as this is the main reason for us embarking on this formulation work after all – to sell something.
Emulsifier Free Claim.
Like every other aspect of cosmetic formulating trends in emulsifier selection abound. Right now we have an emerging niche of ‘emulsifier free’ creams designed around the philosophy that the emulsifier, being a surface-active ingredient may be a source of irritation for very sensitive skins and that avoiding the use of an emulsifier may make the product more suitable for this demographic. Now this may or may not work out to be true but nevertheless the concept is of interest as there is some truth in the idea that surface-active ingredients (of which emulsifiers are a part) can contribute to a products irritation potential.
So if you don’t use an emulsifier to hold the oil and water together, what do you use?
Small amounts of oil can be held in suspension with the use of thickeners/ stabilisers such as carbomer and even, to a lesser degree xanthan and sclerotium gums. These aren’t emulsifiers and neither are they forming an emulsion, more of a suspension but, if the oil phase is light enough and dispersed well enough these products can be made stable through stearic hindrance – the oil droplets are caught up, as if in a fishing net! Sometimes bentonite clays can also be used in this way to bring opacity to the formula and to provide an electrical repulsion layer into the structure to help repel agglomeration of the dispersed phase.
Another option in this space is a modified acrylate copolymers such as Acrylates/Beheneth-25 Methacrylate Copolymer. Although this particular polymer is best suited to surfactant formulations it does have a role to play in leave-on skincare as it has the benefit of being tolerant to a relatively high level of salt and other water-phase destabilisers making it a versatile choice for the ‘emulsifier-free’ concept developer. The fact that the polymer can stabilize a reasonably sized oil phase while remaining ‘emulsifier free’ paired with its low use levels add to the cost efficiency of this solution. Another interesting feature of these polymeric ‘emulsifier-free’ ingredients is their ability to be sprayed which opens up new doors for the formulator and marketing department.
But what if you are looking to create something a bit richer and with an oil phase more typical of a traditional moisturizer?
Modified lecithin chemistry has become accepted technology in the ‘no emulsifier’ space, especially because these lecithin fractions often have lipid enhancing properties and can be sold on their ‘skin compatibility’ and moisture binding powers. In addition, the phospholipid structure also lends its self to active delivery given how similar in structure they are to human cell membranes (well at least in terms of their chemical constituents). Lecithin chemistry tends towards forming a liquid crystal network in the continuous phase, which both traps and interacts with the dispersed phase in an ultra-stable and skin-compatible three-dimensional structure. A number of companies are now offering a range of modified lecithins suitable for everything from light hypoallergenic milk formulations through to super-rich balms which should please marketing departments the world over but from a chemists perspective it is hard to see how these ingredients have managed to escape the ‘emulsifier’ tag.
Ingredient Origin and Ethics.
Another important consideration for the general public and formulators alike is ingredient sustainability and/or ethics. There is a steady yet growing interest in ‘palm oil free or sustainable palm’ concepts the achieving of which is surprisingly difficult. That said, making an emulsion without adding any palm derived ingredients used to be easy – just use petroleum derived chemicals – but these days that is just as unacceptable for a growing number of brands. The reality is, our enthusiasm for embracing the natural revolution has increased demand for vegetable based feedstock and those of us who have been in the industry for a while know that means either palm (orang-u-tan habitat) or Rapeseed/ canola (pesticides and bees).
So today while it is still not that easy to create a palm free emulsion it is not impossible especially given that our previous ‘emulsifier free’ examples are predominantly palm free (lecithin phospholipids are frequently made from Rapeseed, Egg, Soybean and/or Sunflower). In fact, it would be fair to say that the hardest thing about making a palm free emulsion today is not over which emulsifier to choose but in which supporting ingredients can be used to increase stability, viscosity (without gumminess) and overall skin feel.
INCI Name – It Has To Look Good On The Label!
Still under the guise of marketing issues, the issue of INCI names also comes up here, while ingredient maufacturers do have to abide by a ‘truth in marketing’ legislation when they apply for their INCI names (they can’t just make them up) the reality that a natural sounding INCI will sell more and have better shelf appeal than a more chemical sounding ingredient. This reality has really hit home and that can be both good and bad. In some cases we have very average ingredients (in terms of performance) becoming popular because they have a nice name while outstanding ingredients (that are still natural in many cases) are overlooked.
Show Me The Money!
Another important factor in the marketing basket is price. Emulsifiers can make quite a dent in the formula budget and when comparing something natural to a stock-standard petroleum based emulsifier you can be looking at anything from three to five times the price which of course has to be justified. In many ways this is the acid test – will customers put their money where their ethical mouths are or do we have to sell them another benefit? Blending different technologies together can be a good way to increase performance while managing price and this philosophy has kept many of the older emulsifiers options such as glyceryl stearate SE alive and selling well.
Performance benefits of different technology will be looked at more in the chemistry section but as we are starting to see from some of the claims relating to emulsifier free formulations, the ingredient that holds the oil and water together is, in many cases expected to do so much more besides. When the Olive derived emulsifier Olivem 1000 first came onto the market there was a great deal of interest in its ability to act as an active delivery system as well as the ingredient that just happened to make an emulsion possible. That benefit contributed to the ‘emulsifier free’ marketing tagline (it isn’t an emulsifier, it is an active delivery system) while also helping the cosmetic chemist deliver oil-soluble actives deep into the skin (theoretically). This important dual functionality contributed to the immediate success of this technology, success that continues today in spite of the ingredients relatively high price point compared with older technology or ingredients like cetearyl alcohol which also form liquid crystal structures for a fraction of the price! In terms of intergrating new emulsifier technology into the laboratory these days the real question isn’t the price but how many benefits one gets for that price? Water resistance, barrier protection, long-wear characteristics, increased dispersion of actives, viscosity boosting and rheological benefits are all possible thanks to a combination of science and nature!
3) Physical Character.
Something that we may overlook when considering price is the emulsifier’s physical form and this is because we often just think of emulsions as hot process items and so the form of the emulsifier is not really a talking point. But it doesn’t have to be that way. Electricity prices are rising in many countries and even those with cheap power aren’t in the habit of wasting it so liquid emulsifiers that can be used in cold-process applications can help the formulator to tick a few boxes from sustainability through to the economic benefits of saving time and money. The range of liquid emulsifiers is steadily growing and is worth a look, especially for markets that demand an ultra-light touch finished product with little to no wax or butter content.
Of course we couldn’t talk about emulsifier selection without talking chemistry. The emulsifier is the heart of the formula and while it may often seem like, today the chemistry has all been done for you, as I mentioned in the beginning, there are some very challenging problems that await the professional cosmetic chemist that only an appreciation of the underlying chemistry will help solve!
Anionic emulsifiers are, in some ways the old-fashioned cousins when it comes to emulsifier technology given that soap and borax type emulsions were where the industry started but that doesn’t mean they don’t deserve a second look.
Soap-based emulsifiers can be extremely useful in cleansing formulations but can also form part of a very elegant high-end anti-ageing formulation just as long as your selection of actives is chosen carefully.
Anionic emulsifiers carry a net negative charge in solution and because of that they, like the cationics are sensitive to electrolytes. Anionics benefit from the presence of a little monovalent salt or acid up to a point (as the increased saltiness/ acidity increases the critical micelle concentration and activity of the water phase) but above that the formula can critically fail in a similar way to that which we see occurring in over-salted surfactant blends. Salt content can creep up on you in an active formula as ingredients such as Aloe, Sodium PCA, Seaweed Extracts, Sodium Hyaluronate and even some herbal actives can push the limits and as such, freeze/ thaw stability is an essential part of early anionic emulsion stability testing.
In terms of skin irritation potential, the old pharmacopeia driven Sodium Lauryl Sulfate and its ‘harsh on skin’ reputation has largely been replaced and when we talk about anionic emulsifiers we are now more often talking of the elegant phosphate esters renown for their skin compatibility or gentler surfactants such as the lactylates or glutamates making it entirely possible to make an anionic emulsion that is skin-kind and gentle.
Cationic technology for skincare arose from the wool industry and then transferred into hair care. As hair and skin are both keratin derived it didn’t take long for the benefits of cationics to be harnessed in moisturiser technology. Cationics function very well in formulations that are desired to stay on the skin for a long time such as sunscreens, long-wear make-up and barrier creams. This is because their positive, cationic charge adheres them strongly to the surface of the skin, resisting wash off and wear. A practical example of where Cationic emulsifiers have proved very helpful is in preventing sand from sticking to a freshly-sun-screened body thanks also to its anti-static capacity. Like anionics, cationics are also sensitive to what is going on in the water phase and cope best with a relatively quiet external phase rather than one loaded with additives.
Due to their natural capacity for skin adhesion cationic emulsifiers can be more likely to irritate than other chemical families but that said, in many cases the formulator can work around this – formulating to an acidic pH is advisable. New generation cationic emulsifiers tend to favour long hydrophobic tail (s) as these have the effect of reducing the charge density of the headgroup and thus minimizing irritation potential. This, of course, has to be balanced by the ingredients capacity to form and hold an emulsion. As with anionic emulsifiers, cationics do benefit from a little monovalent salt as this can boost the CMC and as a consequence of that, the viscosity, but beyond a certain point the salt becomes detrimental to stability.
It is important to note that in using a cationic emulsifier system the formulator does rule out the use of pretty much all grades of carbomer and even anionic thickening agents such as xanthan, unmodified guar and tragacanth.
Non-ionics remain the first choice go-to emulsifiers for the majority of applications due to their flexibility and low potential for chemical interaction. It is often a non-ionic emulsifier blend that is chosen first when creating creams with high activity levels or hard-to-stabilise ingredients such as salicylic acid, AHA’s, Zinc Oxide or high strength vitamin C. It was ingredients such as Seppic’s Montanov 68 that first got us hooked on the self-emulsifying blend of non-ionic and freed us from the trials of calculating HLB in a complex oil-phase world. The key benefit of a non-ionic emulsifier is its robust salt tolerance. In fact, the addition of a little non-ionic is recommended in ionic emulsions as the mixed micelles that will form tend to display a dramatically enhanced salt tolerance over the ionic alone. While the presence of self-emulsifying blends has made things easier it doesn’t for a moment mean we shouldn’t consider what is going on inside of our product.
The HLB system is alive and well in the non-ionic world and gives us a great insight into where the emulsifier will orient its self and whether it is able to bring any other features to the product. That said, it is also important to mention the existence of more than one HLB system so that one can compare like with like. Between 1949-1954Griffin developed a pretty robust yet simple HLB system and that is the standard upon which the Span and Tween pairings from ICI were arranged. The method produced a scale ranging from 0-20 indicating what percentage of the emulsifier was hydrophilic. The number given was the percentage hydrophillicity / 5 (so the maximum number 20 related to a molecule being 100% hydrophilic). This simple system was expanded upon by Davie’s in 1957 who, thought that some weight should be given to the functionality of the chemical groups on the molecule. This makes sense given the variety of structures available to give a hydrophilic character. This method is widely used today and is one of the reasons that ionic emulsifiers can be assigned a HLB value, it is also the reason that HLB numbers in their 30’s are found (the maximum HLB in this system is 40).
In both systems both the emulsifier and the oils to be emulsified have a HLB attached to them – the emulsifiers have a real HLB whereas the oils have a required HLB. It is widely accepted that the best emulsifier pairings are formed when a high HLB emulsifier is combined with an emulsifier with a low HLB rather than just selecting the emulsifier with the exact HLB you want to achieve. This combination effect serves to best fill the interface surrounding the continuous and dispersed phase, leaving less room for gaps and therefore increasing stability.
Liquid Crystal Emulsifiers
Liquid Crystal Emulsifiers work on the principal of forming a lamella network in the cream, which most closely mimics the skin barrier thus facilitating the effective delivery of actives. Lecithin naturally works this way as does Olivem 100 and various other combinations available to purchase today.
Because of their skin-like structure, liquid crystal emulsifiers are often desired because of their beautiful aesthetics. While it is possible to create a range of textures using almost any emulsifier, depending on what goes into the rest of the formula, it would be reasonable to say that the liquid crystal generating emulsifier is the most fool-proof way of creating a beautiful texture without too much additional work.
Polymeric emulsifiers are a really good option for those looking for elegant and quick cold-process solutions. Often sold as liquid polymer suspensions these emulsifiers can create anything from lightweight sprayable milks through to thicker, richer creams depending on what they are paired with. While not for the natural market these can be quite a sustainable option due to their low addition rate, the speed with which they can form an emulsion and their cold-processing capabilities. That said, polymeric emulsifiers won’t work in every situation. Often these emulsifiers are acrylic acid polymers that tend to form complexes with cationic species. In addition, the general salt tolerance of acrylates is low (reflecting the overall intolerance of ionic substances). But one large advantage over ionic and, to a certain point the non-ionic emulsifiers is their ability to form highly stable emulsions with a very low level of polymer with a non-polar or very slightly polar oil phase. This makes them the perfect emulsifier for a silicone-based emulsion, even those containing cyclomethicone.
4.a) The Chemistry of the Water Phase.
I have mentioned a few de-stabilising and stabilizing factors while talking about emulsifier chemistry and marketing considerations but now it is time to really focus on this. An emulsion is a combination of two immiscible phases held together by what to many looks and feels like magic! What is really going on is a physical rearrangement of components, all trying to get themselves into a position that means they are exerting the lowest possible amount of energy – those dispersed phase droplets are lazy! The dispersed and continuous phases are influenced by everything that comes into the formula and some things are more disruptive than others.
Lowering the Surface Tension.
The surface tension between oil and water is so high they don’t mix unless you add a surfactant (emulsifier in this situation). We understand that and have discussed the different types of emulsifier that we could add but do we understand what other ingredients do to the products surface tension?
Preservatives and solvents can dramatically alter the surface tension between the oil and water droplets. As we see with our emulsifier, some reduction in surface tension is required to facilitate the development of an emulsion but in other cases the changes are catastrophic and can result in viscosity and emulsion collapse.
Glycerin, Propylene Glycol and Ethanol are common additives in a cosmetic product and can all impact on surface tension. All of these ingredients decrease the polarity of the water phase and the influence of that decrease changes depending on the quantity of additive present although the relationship between dose and effect is not strictly linear. Reducing water phase polarity loosens the grip the water has on the dispersed phase somewhat by toning down the intramolecular forces that make water behave as it does – Van Der Waals, Dipole-Dipole and hydrogen bonding. While all emulsifiers depend on these forces to some degree to stabilize the product, the Ionic emulsifiers depend on them more strongly and are therefore most likely to be influenced by their presence.
A Flood Of Ions
We often talk about salt and saltiness in formulating but what we are really talking about much of the time is the ionic strength of (often) our continuous phase. While we all accept that swapping Demineralised Water for sea water might cause us formulary issues, we are less likely to accept that the actives we carefully measure into our water phase are doing the same. Be they acids, bases or salts an ion rich water phase can cause havoc for the stability of a product.
Ionic charge in the water phase can help increase intramolecular bonding and can also help in the formation of an electronic double layer around the dispersed phase which increases stability but things can go too far, especially with divalent salts such as zinc and with strong acids and oxidizing agents such as glycolic and peroxide. In general the cosmetic chemist is looking to minimize chemical reactions in their formula and so any addition of ions should be thought of as fuelling the fire of chemical rebellion. Every emulsion has its limits plus adding too many ions into the continuous phase will give the product a sticky/ tacky/ salty feel when applied.
4B) Tricky Oil Phases.
When compared to vegetable oils, silicones demonstrate practically no polarity as well as a very different chemical structure – flexible chains vs bulky triglycerides. Because of these differences silicone fluids such as dimethicone and cyclomethicone tend to mix poorly or not at all with vegetable oils in the same formula. If the formulator wishes to create a silicone rich emulsion, the influence of this low polarity should be considered and steps to reduce the polarity of the continuous phase would increase stability and take some of the pressure off the emulsifier as the surface tension between the two phases would be lessened.
Silicone emulsifiers are available from the major silicone manufacturers should be the first port of call for all those looking to create a silicone-dominant emulsion, especially where the silicone phase will be large or even dominant. That said, with careful consideration it is also possible to create a silicone-rich emulsion with non-silicone emulsifiers if the chemistry of the whole product is considered and accounted for.
|Solvent||Polarity||Solubility Parameter (A difference of <2 indicates mutual structural solubility). Based on the theory of ‘like dissolving like’ Journal SCC 1985.
|Cetyl Alcohol / Stearyl Alcohol||8.94 – 8.90|
|White Mineral Oil||7.09|
Is your emulsion going to be salty, acidic, basic or contain a high proportion of solvents that are less polar than water or does it contain Hydrogen Peroxide? If so the best starting point is a non-ionic.
At this point I think it’s best if we head into the lab and do some experimenting.
Catch up with those experiments by clicking through here.
- The stability of emulsions in the presence of additives. GA[I]1#, B. JOVANOVI]2# and S. JOVANOVI]2# 1Institute for Plant Protection and Environment, Teodora Drajzera 9, YU-11000 Belgrade and 2Faculty of Technology and Metallurgy, Karnegijeva 4, YU-11000 Belgrade, Yugoslavia, 2001. http://www.doiserbia.nb.rs/img/doi/0352-5139/2002/0352-51390201031G.pdf
- Solute and Solvent Structure/ Polarity. The Pharmaceutics and Compounding Laboratory. UNC Eshelman School of Pharmacy: http://pharmlabs.unc.edu/labs/solubility/structure.htm
- Using Solubility Parameters in Cosmetics Formulation. C.D Vaughan, Cosmair Inc, 285 Terminal Ave, Clark, NJ, 07066. Jan 1985 http://journal.scconline.org/pdf/cc1985/cc036n05/p00319-p00333.pdf
- Introducing Pemulen Polymeric Emulsifiers. file:///Users/amandafoxon-hill/Downloads/TDS-114_Introducing_Pemulen_Polymeric_Emulsifiers%20(2).pdf
- Emulsion Formation, Stability and Rheology. Tharwat F Tadros. https://www.wiley-vch.de/books/sample/3527319913_c01.pdf
- Cationic emulsifiers: An emerging trend in skin care. Angela Paez and Anna Howe, Degussa Goldshmidt Chemical Company. http://personal-care.evonik.com/product/personal-care/Documents/cosmetic-toiletries-manufacture-worldwide-cationic-emulsifiers-for-skin-care-applications.pdf
- Macol CSA 20 Polyether. BASF data sheet. http://worldaccount.basf.com/wa/NAFTA~en_US/Catalog/ChemicalsNAFTA/doc4/BASF/PRD/30093528/.pdf?asset_type=pi/pdf&language=EN&urn=urn:documentum:eCommerce_sol_EU:09007bb28006d4c2.pdf
- Emulsions – Part 2. Klaus Tauer. MPI Colloids and Interfaces. Am Muhlenberg, D-14476 Golm, Germany. http://www.mpikg.mpg.de/886743/Emulsions_-2.pdf
- A Quantitative Kinetic Theory of Emulsion Type 1. Physical Chemistry of The Emulsifying Agent. J T Davies, University Lecturer in Chemical Engineering, Cambridge. http://www.firp.ula.ve/archivos/historicos/57_Chap_Davies.pdf
- Intermolecular Forces. Forces. http://chemed.chem.purdue.edu/genchem/topicreview/bp/intermol/intermol.html