Article by: Perry Romanowski

To become an expert cosmetic chemist, it is not enough to learn the science of cosmetic raw materials and which ones are compatible or not. Indeed, this information is criticial but another part of the cosmetic formulator job is just as important. Evaluating your prototypes.

Evaluating cosmetic prototypes

We’ve previously written about the importance of trying your own formulations. However, we did not get into the details of what to observe while doing that. Here is a system that you can follow which will help make you a formula evaluation expert.

Step 1 – Pick a benchmark

It is almost never the case that you will be working on a product that is completely new to the market. There is always a market leader that you should be comparing yourself to. This can be a competitive product or one of your own formulations. You just need to pick some product as a starting point. This is the thing you are trying to beat.

If you’re looking for a benchmark, it is always a good idea to look at sales information and see which ones consumers are buying most often. This is a good place to start.

Step 2 – Develop your baseline skills

In 2005, I believe that I had the most shampooed head in America. That year I was working on a new shampoo formula and a conditioner formula. I washed my hair over 1500 times. Yikes! While I did develop some redness and an itchy scalp, I always developed keen senses to differences between formulations. To be able to tell differences you have to experience the products.

Each formulation will be different and you may want to focus on some specific aspect however, there are some general things to start noticing.

For hair products the most important characteristics include…

1. Rinse time – how long is takes to be reomved from hair
2. Flash foam – how fast the foam forms
3. Lather feel – does the lather feel creamy or loose
4. Feel in hair – how does the product feel in the hair
5. Spreadability – how easy is it to move through hair
6. After feel – what does hair feel like after using it
7. Dry feel – when hair dries how does it feel
8. Lasting feel – how does hair feel later in the day

For skin products…

1. Rub in time – how long it takes to disappear
2. Greasiness – how does it feel on skin
3. Tackiness – does skin feel sticky
4. Overall feel – after you’ve applied it how does it feel
5. Whiteness – how does it effect skin color
6. Reapplication time – how long does moisturizing effect last

For each of these characteristics you should develop a rating scale (1-5 or 1-10 works well). Then use your benchmark formula and give ratings for each important characteristic. It’s good to repeat this process and see if your scores stay consistent.

Step 3 – Make prototypes

Once you’ve gotten your baseline skills down, test out one of your prototypes. Ideally, you have created a prototype in which you’ve changed only one variable. This will make it easier for you to identify which ingredient can create a signficant change. If you continually test radically different prototypes it will be more difficult for you to get formulating direction from the results of your test.

Step 4 – Test prototype alone

Just as you did with the baseline sample, you should test your prototype a few times and then rate it for the most important characteristics. Be sure to try and forget what your scores are for the benchmark product. At this point it is not that important to be blinded however, as you’re just trying to see if your new prototype is worth further testing.

Step 5 – Compare samples

Once you find a protytpe that you want to explore further, set up a blinded test and do your evaluation. The key to a blinded test is that you have no way of knowing which samples are which. So, if there are color differences keep your eyes closed when evaluating the product. If there are odor differences try to hold your nose. Ideally, you could match fragrances to eliminate this variable.

You can give ratings for the samples or you can just decide which you like better. If you like your prototype better, great! But don’t celebrate just yet. Re-run the test a couple of times to see if you consistently pick the prototype over the benchmark. If you can’t, then you don’t have an improvement.

Step 6 – Get opinions from others

If you are satisfied that your testing shows your prototype is better, then try it out on a few collegues. Give them samples of your prototype and the benchmark and ask them if they notice any differences. Also, have them pick which they like better. Make it a forced choice.

Step 7 – Revise prototypes

Make revisions to your prototype based on the response you get from your own testing and that of the other people who have tried your cosmetic formulation. You really should try at least half a dozen revisions before being satisfied with any results.

Step 8 – Performance tests

If you are satisfied with your in-use tests, it’s time to do some laboratory performance tests. The specific tests you do depends on the type of product you are making. For cleansing products you’ll want to test foam. For moisturizing products, test moisturization. Color products you test wear. There are just innumerable number of tests you can conduct.

Once your prototype outscores your benchmark, it’s time to move forward and push the product along to development. Congratulations!

Now, just one other thing…don’t forget to do an early stability test.

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