One of the most pervasive criticisms of the cosmetic industry is that it tests on animals. In fact, when people learn that I made cosmetics for a living a frequent question is, “do you test on animals?”

No, I’ve never tested on animals (except myself). I think this is the case for most cosmetic chemists. However, it is disingenous to say that the products are not tested on animals. Most aren’t, but nearly every raw material used in cosmetic products has been tested on animals. This is why I’m always troubled by “cruelty free” claims. Everyone is “cruelty free.”

Anyway, the bad press, bad public opinion, high cost and scientist’s genuine desire to minimize the number of animals which get tested on has led to the development of alternatives. These are primarily in-vitro skin cultures which can mimick human skin.

Here is one of the latest technologies that has been developed Evocutis. They have launched the first skin model for the testing of anti-microbial and pre-biotic product claims. The skin model actually simulates the epidermal and the dermal layers of skin.

It remains to be seen whether this technology will replace any real animal tests (it takes time to validate) but it certainly seems like progress.

Stay tuned for more developments in this area…

As a cosmetic chemist, one of the most basic things you need to be able to do is to evaluate formulas and new raw materials. This is one reason we highly recommend that formulators try EVERY product they make. But just haphazardly trying a product will only give you so much information. If you really want to know if a cosmetic formulation is different, you’ll have to conduct a triangle test.

What is a triangle test

Simple put, a triangle test is a study in which you compare 3 samples and pick out the one that is different. Of the three samples, one is actually different while two are the same. If you can consistently pick out the different one, there is a pretty good chance that there is actually some difference that you’re picking up on. You might not always know what the difference is but sometimes that doesn’t matter. The key is that if you can notice a difference then there is probably something different about it.

When to conduct a triangle test

Triangle tests are useful whenever you need to determine whether a change in the formula is noticeable or not. So, they work well for…

• Fragrance evaluations – When you have an odor change and you want to see if there is a noticeable difference.
• New raw materials – To see if there is some performance effect by using a raw material
• Cost savings – Remove a raw material and see if anyone can tell a difference
• Formula development – See if changes you’ve made actually improve your results

Triangle test basics

A triangle test can be done by one person or by an entire panel of people. The former is best when you are making new prototypes and evaluating raw materials. The later is better for making final decisions as it will give you some statistics and numbers to show your boss.

Step 1 – Design your test

The first thing you have to do is figure out what test you’ll run to compare the samples. For odor evaluations this can be a simple “sniff test”. Just put your formulas in a small jars, label them and smell. I like to keep my eyes closed for odor evaluations or do it in a dark room so you can’t be influenced by color. For other products you can use any number of tests such as foam tests, moisturizing tests, combing tests, etc. It really depends on what you are testing and what characteristic you want to notice.

If you are doing a test in which you want to get some useful statistics, you need a panel of about 30 people before you get meaningful data. However, if the differences are significant you’ll be able to make decisions on many fewer test subjects (say 15).

Step 2 – Make your samples

To do a triangle test you need to make two batches of a product. Be sure to create enough to pour off multiple samples. One batch will be your control while the other will be your test. When you are making your samples, flip a coin to decide which batch will be the one you take two samples from and which will be the odd one out. Flipping a coin (or other random process) is important because you don’t want to always conduct the test in which the odd sample is always the test sample.

Ideally, if you are going to test the samples, you should have someone else make and fill the samples. At the very least you should have someone else fill and label them. That way you can be singly blinded and won’t be able to trick yourself.

Step 3 – Test your samples

After the samples are made & labeled, run the test. Evaluate the products in the order they are presented and give an initial guess as to which is the odd sample. It is useful to write down your answer at this point.

Once you’ve tested the samples, it is helpful to re-run the test. This time you should randomly mix the samples and evaluate them without knowing which sample is which. Try to hide the labels. If you are unable to pick out the same sample then the first time was probably a fluke and you’ll want to rerun it a few more times until you can consistently (or not) pick out the same sample.

Step 4 – Reveal the codes

Once you are certain you’ve got the odd sample, look at the codes to see if you picked out the odd sample. If you did, then you can have some confidence that there really is a difference. If you didn’t, there probably isn’t any real difference and the new raw material or the formulation change you made was likely inconsequential, at least for the characteristic you tested.

Step 5 – Determine significance

If you were conducting the test with a panel of people you need to determine if there were statistically significant differences. For people who like statistics you can figure out the Chi squared distribution. X²=? (|O-E|)²/E, where O=observed and E=expected. Or you can use this handy chart. Just find the number of people who have done the test on the left side and see if the number of people who got it correct is on the right.

Click to enlarge

For example, if you did a test with 15 panelists, 9 of them would have to have picked the correct odd sample for you to decide that there was a significant difference.

The triangle test is one of the key tools that a cosmetic chemist has at her disposal. You should practice it often because the more you use it, the better you’ll get and the more useful it will become.

One of the primary tests that you will run on your cosmetic formulations is a stability test. You can read this other post for a complete procedure for stability testing.

In this post I wanted to go over the times when you should do a stability test.

1. New working prototype.

You don’t need to do stability testing on every prototype but when you get to the point of having one that gives good results, you should put up at least a minimal stability test. This would include control samples (4C and RT) and samples at accelerated temperatures of at least 45C. Early stability testing will speed up the launch process.

2. New raw material source.

Often your purchasing department will find a cheaper source of a material that you are currently buying. They’ll then want to use the ingredient right away. However, don’t use it until you have conducted a proper stability test. Just because two raw materials have the same INCI name, that doesn’t mean they are the same. When you run the cosmetic stability test, be sure to run a sample with the current formula along side the formula with the new ingredient.

3. Scaling up to production.

When your formula gets made on in production for the first time, you’ll need to do a stability test. Things don’t always work the same in production batches as in lab batches.

4. New production process.

Speaking of production, another important time to do a stability test is when you make any changes to the production process. Often the compounders will discover faster ways to make products but you’ll need to verify that the product will remain stable before implementing.

5. New packaging.

Even when you don’t change the formula, you may have to run a new stability test. The most common instance is when you change the packaging that the product is sold in. This could be a whole new package type or simply a change in the package resin source.

6. Regulatory requirements.

Sometimes you have to run a stability test just to satisfy the regulatory paperwork of a new market that your product is being sold in.

7. New production plant.

If your product is successful enough it might be produced in a different manufacturing facility. In this case you’ll need to do a stability test just to ensure that the product remains to be of the proper quality.

If you want to create consistently, high quality products, stability testing of cosmetic formulas is one of the primary tests to run.

Many followers of this website have a desire to create and sell their own product. We continue to work on a training program that shows you just how to do that, but in the meantime it would be helpful if you knew exactly the type of testing you have to do prior to selling your product. Note this information applies to US cosmetic products. Other countries may follow slightly different rules.

There are four types of testing you must do before selling your own product. These include micro-testing, stability testing, safety testing and performance testing.

Microbial Testing

This could really be put under safety testing but it is so important that it deserves its own category. Whenever you create a new formula you need to ensure that the preservative system you are using is adequate for preventing dangerous microbial growth. There are two primary types of testing you need to do.

• Micro Challenge Testing – This is a test in which you purposely introduce microbes into your batches, then watch the samples over time to see whether your preservative system is good enough to kill off the microbes. If it’s not, you need to improve your preservation system.
• Contamination test – This is a test you need to do on every batch of product you sell! It is a simple matter of taking a sample and testing to see whether it is contaminated or not. If it’s not, then proceed with packaging & distribution. If it is, don’t sell it!

Stability Testing

Cosmetic stability testing is a study run to determine whether your product will last on store shelves and on your consumers bathroom counter. Stability testing is an important quality test that you need to run in order to sell your products in the US. It is also useful to ensure that when people do buy your product they won’t be dissatisfied with a foul odor, ugly color, or separated formula.

Safety Testing

You can’t sell a product that is not safe. If you do, you open yourself up to litigation which could pretty much ruin any fledgeling cosmetic manufacturer. Safety testing includes things like patch testing, eye irritation tests, and a host of other procedures that ensure consumers will not become serious ill after using your product. The amount of safety testing done depends on the type of product you are going to sell and how different the raw materials are. If you are making something that uses standard cosmetic raw materials, less testing would be needed than if you are using raw materials that are new to the cosmetic industry.

Performance testing

The type of performance testing or claims testing that you need to do depends on the specific advertising claims you’re going to be making for your product. In the US you are bound by the rules of the FTC which state that you cannot promote false advertising. This means if you say your product is going to clean hair, you have to demonstrate that it does. If you say your lotion will moisturize skin, you have to show it does that. There are some industry standard tests but in many cases as a cosmetic chemist, you’ll have to come up with your own reasonable test to demonstrate that what you say about a product is true.

It is not necessary to show the results of any of these tests to the government prior to launching your product. In the US, the industry is self-regulated. However, this does not mean you can skip testing because the FDA can inspect your facilities and levy huge fines on companies that do not have the proper paper work. Be sure to keep track of all your testing procedures and results of any product that you sell.

Testing can be an expensive obstacle to many small cosmetic company launches but it is a crucial step that you absolutely must do before launching any new product.

I saw this interesting approach to hair testing that TRI (Textile Research Institute) is doing this June 2011. They are offering the opportunity for any company to submit samples of shampoos and conditioners to be included in an extensive benchmarking study.

The samples will be tested for speed of rinse, hair lubrication and detangling ability. The test methods were specially developed by TRI but likely are similar to the standard hair tress tests that involve the Diastron & Instron combing machines. These devices work by measuring the force required to pull a comb through a tress.

The thing that makes this most notable is that it could be a significant savings for smaller companies. For example, while it would normally cost $27,680 for a single sample, it only costs $3100 in this group study. That’s a pretty significant savings.

Value of hair testing

While this is an interesting study and a great opportunity to get some samples tested for smaller companies, I’m not sure they’ll get a lot of actionable data. True it will be nice to see how formulas compare to market leaders but you’ll need to do further testing if you want to make your product better. This can start to get really expensive. This is why you should develop some fairly reliable in-house testing method. It will allow you to see the effects of formulation modifications. The test offered by TRI is great for supporting claims but not so useful for giving you ideas about formulation directions.

Still, at $3100 (or less) it is certainly worth it to see how your best formula stacks up to the market leaders.

The number of people I’ve known who work on products that they’ve never even tried has always amazed me . They miss so much when they don’t have direct experience with a product. Perhaps it’s understandable if you are not in the target market for your product, but anyone can safely use most any product and the information you’ll learn from the experience will be invaluable. Here are 5 reasons cosmetic chemists should be trying every cosmetic formula they work on.

1 – Learn the most important characteristics

When I first started working on the cosmetic industry, I was making hair care products. While I always used shampoo, I rarely used conditioner. It seemed like a waste of time. But when I was given the task to make a new hair conditioner formula, I needed to figure out the most important characteristics. Reading about slip, spreadability, and hair conditioning properties didn’t make sense until I tried the product. After using it a few times, I figured out what these terms meant and why they were important. This gave me a basis for evaluating new formulas allowing me to know when I made something better.

If you don’t try a formula, you can’t make it better

2 – Build your powers of observation

Many of the formulas you will work on are ones you’ve tried all your life. But most of the time you use them without thinking. Your mind has become dulled to the experience. When you try a product thoughtfully, you can build your powers of observation and discover all sorts of details you never noticed.

For example, you might start to notice the ease at which your hands slide while applying a lotion, or the length of time it takes to “work into the skin”. You might notice the bubble density of your body wash or shampoo. In short, using a product frequently and mindfully can make you an excellent evaluator.

You can’t make formulas better if you don’t know what to change

3 – Figure out formula problems

Sometimes your Market Research data will come back suggesting there is a problem with your formula. This will be surprising to you because companies do not like to field consumer tests with formulas they know will exhibit problems. Even if all your lab testing shows your formula is good, there may be some subtle things you miss if you don’t try it.

For instance, the product might sting or cause another unpleasant sensation during use. There might be a foul odor which you only smell when it’s exposed to skin, hair, or moisture. You might feel tiny particles that interfere with the experience.

Trying a product identifies unseen problems

4 – Learn the effects of raw materials

A great benefit to trying your formulas is that you learn quickly how different raw materials change the experience. You can read all you want about a raw material but until you actually experience it from a formula, your knowledge isn’t useful. Every cosmetic chemist should have a standard “blank” formula which they can incorporate a new raw material in and try it to determine the effects. This is the best way to learn. Even if the raw material isn’t meant to affect performance, it can have a subtle impact that you would never notice unless you used it.

The fastest way to learn about a raw material is to use it

5 – Inspire new product ideas

Finally, trying cosmetic formulas is an excellent way to inspire new ideas. When you think about the different products while using them, you may start to notice common problems. For example, maybe all the skin lotions you use feel too greasy or don’t last long enough. You should write down these observations and try to come up with new solutions. Product brainstorming while you’re in the act of using a product leads to much more useful ideas than sitting in an office just trying to think.

If not you, who?

As a formulator, you should take pride in everything you make. And if your formula is not good enough for you, how can it possibly be good enough for anyone else?

Do you try all the products that you make?  Why or why not?  Leave a comment below.

Here’s the biggest difference between what you experienced in your college organic chemistry lab versus a cosmetic formulation lab. In an organic lab, you mix chemicals together and hope something happens. Ideally, you get a chemical reaction you expect. As a formulating chemist, you mix chemicals together and hope nothing happens. Cosmetics are mixtures of chemicals that mostly aren’t supposed to react with each other.

Unfortunately, they often do react (or otherwise change) so you need to test your formulas to see how long they will last. This is called Stability Testing and is something a cosmetic scientist spend much of her time doing. In this post, we’ll give a brief description of the test and suggest when, why and how it should be done.

What is stability testing?

Stability testing is simply an experiment in which you create a batch of your formula and put samples of it at different environmental conditions for a set period of time. These conditions vary in temperature and light levels and are meant to simulate what will happen to the product during its life cycle.

At select intervals you evaluate your samples for various physical, chemical and performance characteristics to see how they have changed. If the changes are minimal according to your company standards, then your formula is said to have “passed” stability testing. This means you can have confident that when the formula is shipped to stores and ultimately customers, it will still be as good as when it was first manufactured.

The underlying assumption in stability testing is that increasing storage temperature speeds up any aging reactions that will occur. A handy rule of thumb is that a sample stored at 45C for 8 weeks is equivalent to one that is stored at room temperature for one year. This isn’t an exact predictor, but is good enough for the purposes of cosmetic products.

A sample stored at 45C for 8 weeks is equivalent to one stored at room temperature for a year

When do you perform stability testing?

Since you’ll be making hundreds or thousands of prototypes during your career, it won’t be practical to run a stability test on all of them. You’ll also find that changes happen so rapidly at your company, you won’t have time to properly test many of your formulas. But there are times when you need to do stability testing. Here is a short list of some of the most important times to conduct a stability test.

1. New prototypes – Whenever you make a new formula and are satisfied with the way it performs, you’ll want to do a stability test to ensure that it will stay together. Don’t bother testing all your prototypes, just the ones that work the way you want.

2. New raw materials – Whenever you have to change the fragrance, color, or other raw material in a formula, you’ll have to do a stability test to make sure there aren’t unacceptable changes. Also, when you have a new raw material source (or supplier) you’ll want to run a test.

3. New manufacturing procedure – Manufacturing is always trying to find faster ways to make formulas. This often means they change some order of addition or shorten mixing time. Whenever changes like these happen, it could affect your formula. Run a stability test to see if the change is acceptable.

4. New packaging – Cosmetic products change their look almost yearly so packaging is constantly being modified. Whenever you get a new package, you’ll have to determine if the formula continues to be compatible. Stability testing helps ensure that it is.

How do you stability test a cosmetic?

There are no set rules on how you must conduct a stability test for cosmetic products. Of course, for cosmetic OTC products like sunscreens, AP/DO, or dandruff shampoos the FDA has specific stability test requirements that you have to follow. See the FDA website for more information.

Here is a basic format you can follow for conducting a cosmetic formula stability test.

Step 1 – Make your batch. Calculate how much to make based on the number of samples you’ll be using for the test. It’s a good idea to make 30-40% more than you think you’ll need.

Step 2 – Fill your samples. Ideally, you’ll have the correct packaging but don’t count on it. When appropriate, fill glass jars with the product along with the finished package. In stability testing, you want to do both glass and packaging if possible. The number of samples depends on how much testing your doing but at minimum you should have 2 samples for each storage condition.

Step 3 – Take initial readings. Once you have a sample filled test it for all the characteristics you’re going to evaluate later. The exact tests depend on the product but minimally you’ll want to record notes about the appearance, color and fragrance. You’ll also want to take pH and viscosity readings. For aerosol products you will test spray patterns.

Step 4 – Put samples at different conditions. Stability testing requires different temperature and light conditions. Some standard temperatures include 50C, 45C, 37C, 25C (RT), and 4C. You’ll also want to conduct a freeze/thaw stability test which involves cycling your product through 24 hours of freezing then 24 hours of thawing. Different lighting conditions involve a fluorescent light box and a natural light box (to simulate sunlight).

Step 5 – Evaluate the product. Samples should be evaluated at the following intervals. 2 weeks, 4 weeks, 8 weeks, 12 weeks, and 52 weeks. Only the RT, 37C and 4C samples will be evaluated after one year. The highest temperature samples and the light exposed samples only need to be evaluated for the first three test intervals. The evaluation tests should be the same ones you conducted when taking your initial readings.

Step 6 – Determine stability. After 8 weeks you can confidently decide whether your formula is stable or not. Nearly all products will exhibit some change so it will be up to you (and your boss) to decide whether the product passed or not.

Early in your career, stability testing will be one of the most common activities you’ll do. If you can create a system that you consistently follow, you’ll avoid burn-out and be able to confidently communicate when a product is appropriate to launch.

How does this compare to your company’s stability procedure? Leave a comment and let the rest of the cosmetic chemists here know.