Having studied social sciences and humanities at post graduate level, I am well versed in the practise of primary and secondary research but I hadn’t really needed to use the scientific method. All I knew was this method wasn’t of too much use when studying the complexities of societies or human nature.  That said, I was probably introduced to the scientific method when doing some units in anthropology (which I loved) and I probably did it when studying sciences in school but until venturing into cosmetic science I had not practised the scientific method on any meaningful level.  I don’t call myself a scientist but I do use this tool when formulating natural cosmetic products.

The scientific method is a valuable device for making products of a high standard; that can be made repeatedly and accurately.  It is a way  to be systematic when formulating cosmetics and should inform most of the stages from conception to bringing the final product to market.  So, what is the scientific method and how can it be used to make great products?

Broadly speaking, the scientific method is a set of stages a person goes through to test a claim or hypothesis. However, the stages are not linear in nature and they can be adapted for distinct types of scientific inquiry.

Below is an infographic about the general steps within the scientific method.

How is the scientific method used when making cosmetic products?

When formulating it is important to experiment, test, record and observe in a methodical way. Below is an example to show how the scientific method can be utilised when developing cosmetic products.

HOW I USE THE SCIENTIFIC METHOD WHEN FORMULATION

So, I want to make a cream with a new emulsifier. At this stage my brain says “oh I fancy trying out that new emulsifier, I wonder what it is going to be like? I think I might make an emulsion with lots of oil in it.”  What do I do?

Here is a basic summary of the steps I might take:

  1. Research the specific emulsifier.  Peruse the supplier’s data/sell sheet as that will give lots of information.  They have normally done a great deal of work testing their ingredient as they want to sell it.  I usually take interest in things like the pH it works well at, what ingredients they advise to avoid or use minimal amounts of.  I look at the processes and methods they employ and do a google search to find out if there are any products on the market that use this emulsifier.  Often the ingredients list will give a lot of information.
  2. Start formulating on paper (or excel sheet). I use the knowledge I have gleaned from the supplier’s research as well as my own experience when formulating. But, this is a starting formulation and must be made in order to know if the emulsifier works the way I want it to. It could be said that the paper formulation is my hypothesis.
  3. Make a prototype. I carefully make a physical cream with the emulsifier, recording the method, conditions and details of how I make it, including any errors. The first formulation contains the recommended use rate for the quantity of oils used in the formulation, but it is an expensive emulsifier and I need it to be cost effective. I have to be aware that the company may also use the higher bracket of said emulsifier in their sales copy.  On that basis I formulate the same cream with different levels of emulsifier to find the optimum level.
  4. I do a stability test to see if the emulsifier works in my formulation. The one with the least emulsifier is not stable, it has separated however the others are fine. The stable one with the least amount of emulsifier is chosen.  To ensure this is truly stable, it is made again and tested again.

But I keep thinking about the one that didn’t pass the stability test.  I wonder, “Maybe it had nothing to do with the emulsifier, maybe it was something else?” I hypothesize what this might be and test it out again.  I rewind back to stage 2.  This might happen a few times while I try and trouble shoot especially if other things spring to mind.

Using the scientific method in formulating skincare is not difficult, providing good records and methodology are used.  It is easy to have negative results with a formulation and be tempted to change a few things at once. I have been guilty of this myself.  Then again, there are also times when I know I am so far off the mark I end up using the experience of the first prototype to start all over again. But when close to the desired result, it is always better to change just one ingredient at a time – it might be time consuming but at least I know what is happening and why.

This is a pretty simple whipped Shea butter.  I used refined organic Shea that had been pre-tempered. It might work with raw minimally processed types.  It is very occlusive and when I made it initially it felt quite greasy so I added some organic tapioca starch to cut the oiliness a little. I didn’t want to dry it out completely as that would be pointless.  In my opinion it sinks into the skin quite quickly for what it is. Below is the formulation and method.  Its scented with organic Orange and Lavender essential oils. As this is a leave on product it is better to use distilled Orange oil as I understand it is not phototoxic.

The formulation:

INGREDIENTAMOUNT USED PERCENTAGE 
Organic Shea Butter150g93.75
Organic Tapioca Starch9g5.62
Organic Orange Essential Oil0.5g0.315
Organic Lavender Essential Oil0.5g0.315

Method:

  1. Partially melt the Shea Butter. Mine was half melted when I decided to whisk. After the inital whisk the temperature was 29c.  I then added the Tapioca Starch and essential oils. 2. I whipped every 10 minutes.  This is what it looked like when it was 27c3.  I carried on whipping, every 5-10 minutes.  This is the final picture after I whipped it at 23c.

I initially used the ‘add ingredients as I go along’ method of formulating and calculated the percentages afterwards.  You might want to just use this as a basic guideline and adjust accordingly especially if you like things a bit neater. This is a good starter, but you could easily swap out the tapioca starch for another starch and of course use different essential oil blends. You could probably get away with softening it slightly in a bowl of hot water rather than melting it.  Many people swear by using this method or continually stirring to stop it going grainy.

Shea butter has a really nice consistency. Its not extremely hard and quite easy to whip. Its very moisturising and many people use it on its own for dry and itchy skin conditions. Whipping it is a great way to make it user friendly as it is quite dense otherwise.

If you have problems with grainy Shea or want to know how to do all sorts of different things with it then you will find the book Working with Shea by Lise Andersen very useful.