Often on forums I visit, people will post formulations, or little experiments they are doing.  We get some lovely looking products – creams and lotions, shower gels etc.  There is generally one person that might point out that there is ‘bug food’ (normally without even knowing the level of said bug food) and that they should make sure their preservative will ‘cover it’.  More often than not they are talking about things like starches, floral waters and  honey.  In this post I am going to explain, using rose water as an example, why generalising about ingredients is not particularly helpful and can be a bit of a problem when formulating. Firstly, there is the issue of testing our products.  We only know for sure if our preservative will ‘cover’ anything is by testing them.  Secondly, in most water containing products there are enough ingredients that are ‘bug food’  i.e. emulsifiers, butters and waxes, that can put a strain on a preservative. So, what is the problem?

Lets look at the issue more fully using the example of floral waters or hydrolates.  So floral waters like rose water first and foremost contain water, small amounts of essential oil and  in some cases it has some solid vegetable matter.  We all know that bacteria, yeast and mould need moisture to survive. But water is found in large amounts in most of our water containing formulations. Water is unavoidable in this case, and as we know, water is the life force of every organism, we just have to make sure that starting out our water is clean.  The same applies to other ingredients.  As stated, hydrolates  contain some essential oils left over during distillation. In the case of Rose water, it will probably have a large amount of phenyl ethyl alcohol.  Phenethyl alcohol is quite a strong anti microbial so is likely to help keep the product clean of some bacteria. But what about the solid matter?  Well the solid matter, doesn’t so much as provide food for microbes, as harbours them. So by using a floral water with lots of solid vegetable matter we risk introducing microbes to our formulation.

But the thing is, the levels of solid matter really depend on the individual floral water, how well filtered and how clean it is.  Recently I have been on a bit of a hunt to find a strongly scented rose water that is preservative free.  I have noticed there is a great variety in their quality –some have been preserved, some not, some have been  cloudy and some with sediment and some crystal clear. Some are strongly scented indicating a lot of essential oil and some have barely no scent at all.   I have purchased some from skincare brands that have a period after opening of 6 months (which indicates it would have been tested) and have been extremely strong in scent and have no preservative.   There are also ones branded for the food market that would have also had stringent tests conducted.  This also leads me to believe that it really does come down to the quality and purity of the product.

All this taken into consideration,  I have seen many,many products on the market with high levels of floral waters, so it is not impossible to formulate with them safely!  One thing is for sure, when you are purchasing a floral water, make sure you get the certificate of analysis which will tell you exactly how clean your product is.  If you have the capability it might also be a good idea to test your floral water for contamination, and it also goes without saying, if you want to sell then you need to test that your preservative works and your over all formula is safe.

Happy formulating!

 

I really like things that transform while you are using them.  Powders to cream, blooming bath oils that change from oil and emulsify in water, that sort of transformation.  So I decided to make an oil-gel to foaming cleanser that could probably be used as either a facial cleanser or a shower oil.  I made this quite quickly after researching the ingredients so it is essentially a ‘bare bones’ formula but I hope you can gain some inspiration!

What you need to make one of these is a vegetable oil for your base base, an oil soluble surfactant or a combination of them and something to create the gel.

I used a base oil of Sunflower oil and  some Dermofeel Viscolid – which has the INCI of hydrogenated vegetable oil – as a thickener. It can be used between 5-15% depending on the viscosity you are after.  For a thin gel no more than 5% is needed.   I used Lumorol as my oily surfactant which has the INCI of  Laureth 4, Mipa-Laureth Sulfate, Propylene Glycol and is not very ‘natural’ but it was all I had to hand.  That can be used up to 50%.  I also used a nice natural emulsifier called Sebumol 1000  to support the surfactant.  That has the INCI of Polygylceryl-3 Polyricinoleate, Polyglyceryl-3 Diisostearate and Polyglyceryl-3 Caprate – which is a great natural alternative to polysorbate 80.

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I mixed them all together in a glass jar and heated them to 80-85c whilst stirring.  Then stirred until it reached room temperature. It only started to properly gel at 25c.

So, what is it like?  You can see from the picture that it is a nice hazy gel and goes on smoothly.  When it is mixed with water it gives a nice creamy foam.  My skin feels clean BUT I think it is still a little too cleansing and wondering if I could reduce some of the surfactant so that it is not so cleansing or adjust the ratios of the Sebumol and Lumerol?

Oh and I also added Rosemary essential oil as it smells nice and refreshing.

Below is a picture of the gel on my hand. As you can see it isn’t completely clear but that isn’t something I mind and foams up pretty nicely. Before foaming it kind of emulsifies into a cream which is quite nice,  I think that adding something to change the colour would be nice or maybe using an oil infused with alkanet root for a pink colour or even Sea Buckthorn berry for an orange hue. All in all, this starting formula is really quite good but could also do with some little tweaks here and there.   Note: if you are going to make something like this make sure you put it in a bottle with a lotion pump or airless bottle – as there is not preservative it could easily get contaminated if water gets in.

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I have been testing out a new preservative.  Its based on an organic acid and some polyols. The INCI was not offensive even for the most purest of natural formulators or customers so I thought it would be a nice idea to try it. Also, it looked to be easy to use as compared to others on the market.  It has also been used by some pretty big brands as the only preservative so I know it can work.

Process wise, it can go in the heated water phase up to 90c so if you have problems controlling your temperature it won’t make much of a difference.   It can go in the cool down phase as well and is recommended for use in just about any formulation type you can think of – anhydrous ones like cleansing balms, emulsions like creams and lotions, solutions like toners and detergent surfactants like shower gels and facial cleansers.

All in all I have been pretty excited about using it.

The manufacturers only advice was that care should be taken when using with clay’s as the metal ions  can interfere with the formula and change its colour to ‘faintly mild orange’ which, they say, is barely detectable.   So, I thought bearing all this in mind,  it would be perfect to use in an emulsion.

I made a body cream in the normal way, including the preservative as directed by the manufacturer.  I decided to put it in after the emulsion was formed (at around 60c)  and it initially thinned the emulsion which was a worry, however it did thicken nicely after 24 hours.

I did a quick and dirty 48 hour stability test at an unusually high temperature and it was stable – it did not separate, there were no changes in colour or scent.  All in all it looked promising.

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However, after just over two months at room temperature, as you can see from the picture, the colour changed from a nice creamy colour (left) to the salmon pink/orange colour on the right . My thoughts are that although there is no clay in there, there is enough metal ions floating around to cause this colour change.  So what would be the plan? First off,  I am going to use a chelating agent like Sodium Phytate/ Phytic Acid which will help bind the metals and hopefully stop it from discolouring the product.  I might also see if it is light that causes the problem by keeping a batch in a cupboard or a in a dark glass jar.

So there you go! Although this preservative looked promising it has had some problems which could only be identified by experimenting with the product. This is also a reason why performing stability tests is so important – without waiting and observing we do not know how our products will change over time.

I was recently asked by a customer if hydrogenated vegetable oils were ‘bad’ for our skin.  She was looking at my ingredient list for the Hydrating Beauty Balm which had listed hydrogenated vegetable oil; part of the olive wax I use.  I mentioned that using a substance on the skin could have different physical effects than using them in food and that I understood that when ingested trans-fats  can be a physiological disaster.  I assured her that hydrogenated vegetable oil is totally safe and beneficial to use in skincare.

Why use them?

There are a number of reasons why you might want to use hydrogenated vegetable oil above other types of oil thickeners.  Firstly, Hydrogenated oils are known for having a very long shelf life.  Longer than the original oil.  That means they do not go rancid quickly.  Oxidised oils are not good for the skin.  Secondly, because they are generally standardised, the product will always be the same.  Using a natural butter or wax may vary from batch to batch which means the quality of the product will change for the better or worse. Thirdly, fully hydrogenated vegetable oils have the ability to thicken oil without changing the sensory feel of our products which is great.

Some people feel that hydrogenated vegetable oils are not good because of the way they are processed as it uses ‘chemicals’.  Normally oils or fats have different levels of saturated and unsaturated fats naturally present. Saturated fats are hard at room temperature and unsaturated fats are liquid at room temperature. Hydrogenation is a way to turn all or some of the unsaturated fats into  the saturated form using a chemical process which involves hydrogen (that stuff in water) and a catalyst, normally nickle (a metal).

So what is the process of hydrogenation?

Lets take Jojoba oil as an example.   This involves heating the oil with steam to about 160c in a pressurised  container. A nickle catalyst is introduced as it  is released into a converter.  When ‘charging’ is complete hydrogen gas is added whilst the catalyst and the oil are mixing which creates a uniform slurry.  The reaction of the oil, catalyst and hydrogen creates heat.  Once the temperature has reached about 205-230c the reaction is complete and cold water is added to cool it down. After this there are a series of processes which remove the hydrogen gas and nickle, this happens with filtration, using citric acid as a chealant (binds to metals) and further filtration so that there is no residue of nickle left in the wax.  (1)

If you see a wax that you would normally see as an oil such as Apricot, Hemp or Almond wax , the likelihood is that it has been hydrogenated. Either it will be fully hydrogenated and have the prefix ‘hydrogenated’ before the botanical name in the international nomenclature (INCI).

Olive Wax has the INCI of hydrogenated vegetable oil, Olea europaea (the one I use)

Almond wax has the INCI of hydrogenated vegetable oil, Prunus amagdalus dulcis

Apricot wax has the INCI of hydrogenated vegetable oil, Prunus Armeniaca Kernel Oil

There are also vegetable butters like avocado butter and almond butter which contain the hydrogenated variety of the vegetable oil and the oil itself – these are a result of partial hydrogenation.  The INCI will also look similar to the above.

Hydrogenated oils are normally used to thicken a product. They will thicken the oils in lotions and creams.  They are also a great alternative to using beeswax if you are going for the vegan market.

But are they safe to use in skincare?

Whether a hydrogenated vegetable oil is considered safe depends on the starting oil as hydrogenation is only about changing some of he double bonds into single bonds or making something that is unsaturated, saturated.   All the oils used in skincare in the West are considered safe according to the Cosmetic Ingredient Review but there are other things to consider.  We may want to avoid using one synthesised from Peanuts or Soya bean if you are worried about adverse reactions from allergens.

Some people are uncomfortable with using hydrogen and a metal catalyst in the process but when vegetable oils are processed they often use similar processes to extract the oil from the raw material.  Of course there are some oils that are cold processed but often this is half the story, a great many cold processed oils also go through some kind of chemical extraction. With both oil extraction and hydrogenation, there are steps to ensure there are no solvents left in the final product.

We all make choices and have our limits with how far we want to push ‘natural’ so if you don’t want to use hydrogenated wax or butter there are other options.  Waxes like Carnauba and Candellila wax come straight from the leaves of the tree.  They are harder waxes that melt at a much higher temperature than most hydrogenated waxes or beeswax. You also have the aromatic Bayberry wax which is scraped off the fruit of the Bayberry shrub. There are also various butters on the market that vary in consistency, texture and melting point. It is just a matter of testing them to see if they have the effect you want in your natural, botanical formulations.

References:

(1) Seventh International Conference on Jojoba and Its Uses: Proceedings, edited by A. R. Baldwin