Step 1 — Define your product
Before you get started, you need to think about what you are going to make. Figure out what functions you want your product to achieve. Is it a cleansing product, a moisturizer, a coloring product, or maybe a combination of factors? Also think about the aesthetic characteristics like color, thickness, clarity, etc. and the cosmetic product form. Write these parameters down so you’ll know when you done whether you’ve been successful.
It is always helpful to have a target product with characteristics that you are trying to match. Be sure to get a sample to look at and feel.
Step 2 — Find a starting formula
Next you need to figure out a good starting formula. Starting formulas can be found from a variety of sources. You can look at some of the most useful cosmetic science books. You can also look at online formularies like the one from Happi.com or Chemidex.com. Raw material suppliers like Croda and Rhodia also have formularies that you can use. Another useful source is patents. You can use Google patents or the USPTO.gov website to find formulas. Of course, you can also talk to a colleague who may be able to share one of her starting formulas with you. Finally, if you work at a big company, they will have a big archive of old formulas that will give you a great starting basis.
Remember, starting formulas are not meant to be finished formulas
Step 3 — Prepare for your batch
Once you have your starting formula, you’ll want to determine how much you want to make and create a spreadsheet which lists out how much of each ingredient you need. Then you’ll need to list the specifications that you will test when the batch is finished. After that you’ll have to gather up all the raw materials and processing equipment needed to make the batch. Next, put on your safety glasses & start making your batch.
Step 4 — Making the batch
Making a cosmetic product is much like cooking. You weigh or measure out your ingredients, mix them together as dictated in the procedure and heat & cool as required. During the entire process you should be writing detailed notes and observations in your lab notebook. These will come in handy when you need to make refinements for future prototypes.
You almost never make a perfect batch on your first try
Step 5 — Test your batch
Once you’ve finished your formula, you’ll want to test it to see how successful you were. After letting the sample equilibrate to room temperature, take appropriate measurements like pH and viscosity to see if you are within specifications. Also, weigh the batch to see how much water weight you lost during the heating and cooling process. If you’ve lost more than a few % of water you may want to add water to make up the difference. In addition to specification tests, you should also do some performance tests to see how well the product functions. At the very least try the product on yourself. If the formula meets your satisfaction then you’ll want to do a stability test.
If you won’t use the product you made, why should anyone else?
Step 6 — Revise formula and Repeat
After you’ve tested the product and determined where it doesn’t quite measure up, you’ll need to make adjustments to see if it can be improved. I’ve found that knockout experiments are the most helpful way to figure out the effect that every ingredient has on the final formula. Once you know what the ingredients do, you’ll know which ones to increase or decrease to improve your formula.
After a dozen or so revisions, you should have a formula that meets your needs.
Cosmetic formulating is as much an art as it is a science. As you gain more experience, you’ll find ingredients that you like to work with and others that you avoid. You’ll develop your own style and ideally make products and formulas that are genuinely unique to you. I always liked to add a “signature” in my formulas by using some ingredient at a % that included the number 44. It didn’t usually have much affect on the formula but it did make me feel like the formula was my own creation. And it was.
Good luck in your formulating career!