As a formulator one of the hardest things to do is to create new formulas from scratch. This is because formulations are a mixture of chemicals and it is extremely difficult to predict what will happen when multiple ingredients are mixed together. If you remember phase diagrams from physical chemistry class, it’s like that but even more complicated.
This is why formulating continues to be a mixture of art plus science. No one has created a computer program that can tell you exactly what ingredients to mix together and in what proportion to get a formula that functions the way you want and is loved by consumers. This is ultimately good for cosmetic formulators as it ensure job security for at least a little while longer.
Fortunately, the process of coming up with formulations is not as complicated as the prediction of what happens when you mix ingredients together. If you’re faced with creating a new formula or evaluating a new ingredient here are some tips on how to determine the cosmetic ingredients to use and how much to add.
Figure out what your product is supposed to do
Of the thousands of raw materials available there are only three basic types in cosmetics. And of these three, only one type actually provides the functional benefit to the formula. This is what I call the functional ingredient. We’ve previously written about functional ingredients.
When formulating, decide what your product’s primary purpose is (cleaning, conditioning, moisturizing, holding hair, changing skin color, etc.) then find the right functional ingredients for that purpose. If it’s a cleansing product you’ll most likely be using an anionic surfactant. Moisturizers are a bit more complicated and you’ll use occlusive agents, humectants and emollients.
Once you identify your main functional ingredients, figure out what solvent you are going to use. The vast majority of cosmetic products use water as the main solvent. It’s mostly benign and relatively cheap as ingredients go. If your functional ingredient is compatible with your solvent, great! If not you’ll need some aesthetic ingredients to make it more compatible.
How much of an ingredient to use
After you have your solvent and main functional ingredients you can start making crude prototypes. But you’ll have to have a starting point for your functional raw material. Here are some suggestions.
1. Start with the amount suggested by manufacturer - Suppliers almost always overstate the amount that you actually need but it’s good to start high because that will let you know the best performance you can expect from an ingredient. Typically, the more of an ingredient you use, the greater the effect you will observe.
2. Use an amount that works with your formula costs - Once you find a level that gives you the performance you want, you can then start optimizing to find the right level. The right level is the level that gives you the maximum required performance at the minimum cost. When you are formulating your project group will give you a maximum cost for the formula. Determine the contributing cost of your ingredient and reduce the level to one that doesn’t go over your maximum formula cost.
3. Use a minimum amount - After you find a level that works with your formula costs, try reducing the level even more. This won’t be the formula you go with to marketing but it would be helpful for you to know how low you could go without losing too much performance. Eventually you will be asked to reduce formula costs so you should know if the ingredient can be reduced even further.
4. Guess how much to use then optimize - If you can’t get the supplier to suggest an amount to use you can just pick an arbitrary amount and start from there. Anything from 1% to 10% is reasonable for most ingredients. Then after testing you can cut the amount in half of double it depending on whether you saw an effect or not. Incidentally, if your supplier doesn’t give you a suggested starting level you probably shouldn’t be working with that supplier.
Cosmetic formulating continues to be guessing game when it comes to the amount of ingredients to add to your formula. There are basic guidelines for each type of ingredient but for your own specific formulas the only way to know for sure how much to add is to try a level out and adjust from there.