There was an interesting article about ‘clinical testing’ of cosmetic products. Essentially, the authors suggest that the science used to support the claims made by the nutrition supplement product Inneov Sun Sensitivity is faulty, biased, and practically worthless.

I don’t yet have access to the original BJD article but if the news report is accurate, indeed this is sketchy science. The extraordinary claims are not quite supported by the testing.

Unfortunately, this is usually the case with studies designed to prove a point rather than discover a truth. In the cosmetic industry, it is called Claims Testing.

Let’s look at some of the questionable testing that goes on in the cosmetic industry and suggest how it could be improved.

Using consumer opinions to make claims

This happens all the time. When a cosmetic manufacturer wants to make a strong claim their product, they go to consumers and see what they think. If it is a bad study, consumers will be given a product that they use for a certain amount of time, then they answer questions about it. Their answers will then be used to support claims made about the product.

Why is this questionable?
There are a variety of reasons this is not good science but the biggest is that consumers are easily fooled. If they like how something smells or feels, or they just enjoyed the overall experience, they will be inclined to rate everything higher. For example, if a consumer likes the fragrance of a hair conditioner, they’ll be much more likely to rate highly the performance of the product for shine, detangling, manageability, etc. The positive feelings about the fragrance has a “halo” effect on all other attributes.

So, if you ask a consumer whether a product made their hair more shiny, the answer will likely be influenced by something that has nothing to do with shine at all!

How to make it better.
If you are really interested to know whether a product improves a specific attribute consumer testing isn’t the best thing to use. Better are lab tests or trained panel tests. However, if you want to use consumer tests then at the very least make it a double blind controlled test. This means that you give them your test product and a control product that look and smell the same. You should then have the products made by someone who is unaware of the test purpose so you don’t know which samples are which. You should also use a minimum of 30 people for the test however, >100 is even better.

Using improper controls

This is a fairly common occurrence in the cosmetic industry. Perhaps most common is in studies done by cosmetic raw material suppliers. They show impressive looking data that is much less so when you consider the control. Frequently, a raw material will be evaluated against a ‘no-treatment’ control. It should come as no surprise that any skin lotion will improve skin condition when compared to no treatment.

Why is it questionable
The problem with improper controls is that you set up a test in which you know your product isn’t going to fail. You already know there will be a positive outcome. This is not science.

How can you make it better?
The way to make this testing better is to use a proper control. Not only should you have a positive control, but you should have a negative control. Suppose you want to know if your moisturizing shampoo makes hair easier to comb. Your proper controls would be a Normal shampoo and an alternative Moisturizing shampoo. Compare the performance of all 3 to answer whether your product is indeed better than other moisturizing products.

Using unrealistic lab tests to support claims

To make incredible claims, products are often taken into the lab and tested in ways that specifically support the claim. For example, to measure hair shine a single fiber is sometimes used. This is fine if the claim is that it makes a hair fiber more shiny but it doesn’t answer the question whether it makes bundles of hair more shiny. Similarly, the thickness of a hair fiber is measured using a laser micrometer. This is supposed to support “thicker hair” claims even though the increase in thickness is something consumers would never be able to notice.

Why is it questionable
The reason that these tests are questionable is that they create support for claims that are different than the consumers might believe. If a product claims to make hair 50% more shiny and the data is based on single fiber tests, it really isn’t true.

How can you make it better?
Lab tests like these are excellent to use while developing new products and refining prototypes. But you can’t just stop with this testing. Additional testing should be used to check to see whether the changes are noticeable to a trained panel and ultimately a consumer.

There is some excellent testing going on in the cosmetic industry but it could be improved. Using proper controls, minimizing consumer halo effects, and validating lab tests with trained panels are simple measures that could lead to significant improvements.

In college, most chemistry classes were focused on creating chemical reactions. We were constantly challenged to figure out what reaction would happen when you mix chemicals together.

Cosmetic science is not usually reactive

So, you might find it surprising that cosmetic scientists usually do the opposite. We mix chemicals together and hope that nothing happens. In a cosmetic formula, chemical reactions are bad. They are a sign of instability and we do everything we can to prevent them.

This drive to make nonreactive systems might lead you to wonder whether all those chemical reactions you memorized in Organic Chemistry were a waste of time. And if you work as a cosmetic formulator, you might wonder, “Are there any chemical reactions in cosmetic science?”

Yes, there is!

Reactive cosmetic products

While most of the chemical reactions in our industry occur at the raw material suppliers labs, there are some cosmetic products specifically designed to chemically react.  Here’s a list of the most common.

Permanent Waves

These products are designed to permanently change the shape of hair. People with straight hair often use permanent waves to get a little curl in their hair. A permanent wave formula has a reducing agent like thioglycolic acid that reacts with the di-sulfur bonds in the cystine amino acids breaking down the hair structure. Hair is first shaped into curlers, then the product is put on hair. It begins reducing hair and is rinsed with water to stop the reaction. A neutralizing chemical like hydrogen peroxide, is added which reforms the di-sulfur bonds into the new configuration.

Hair Relaxers

These products do the opposite of permanent waves. They make curly hair permanently straight. The method is similar you chemically break down hair, reshape it, then reform the protein bonds in the new configuration. Sometimes ammonium thioglycolate is used but most often it is sodium hydroxide or lithium hydroxide. The compounds break down the di-sulfur bonds in hair and the neutralizing step stops the reaction.

This is the most damaging chemical treatment for hair.

Hair Bleach

Hair bleaching is a process used to turn brunettes into blonds. You didn’t really think that there were that many blonds in the world did you? Hair bleach is a chemical reaction between melanin (the material in hair that gives it color) and hydrogen peroxide.

Hair Colors

Hair coloring is a slightly more complicated version of hair bleach. It uses hydrogen peroxide to break down hair’s natural color, then the peroxide also oxidizes a polymeric reaction with dye monomers. When the dye polymerizes inside the hair, it creates a color molecule that is too big to easily come back out.

Skin Darkening

These products are designed to give fair-skinned people a tanned look. They work by using an ingredient called dihydroxyacetone or DHA. It reacts with the proteins in the stratum corneum via the Maillard reaction to produce the brown (although sometimes orange) color. All the steps haven’t been worked out, but basically when DHA is exposed to skin protein, it is converted to pyruvaldehyde, which then reacts with arginine, lysine, and histidine amino acids in skin to form brown/yellow pigments called melanoidins.

Be sure to see Kelly’s article about DHA in Cosmetics & Toiletries magazine.

Depilatories

These are products designed to help people to remove unwanted hair. The primary active in these types of cosmetics is some version of thioglycolic acid. The acid reacts with the cystine amino acids in hair and breaks down the S-S linkages. The hair is reduced to a jelly like mass that can then be wiped away. Note this is the same reaction as in permanent waves.

2SH-CH2-COOH(thioglycolic acid) +R-S-S-R(cystine)—–> 2R-SH + COOH CH2 SS CH2 COOH (dithiodiglycolic acid)

Chemical reactions are not the primary focus of most cosmetics, but there are a few reactions so don’t fret. Memorizing those reactions in Organic Chemistry wasn’t a complete waste of time.

I put together this video about cosmetic ingredient nomenclature that you might enjoy.  It’s about 15 minutes long and gives you a basic introduction to how cosmetic ingredients get their names.

Just click on this link

As formulators of cosmetic products, we must ensure the products are safe for consumer use. The Food, Drug and Cosmetic Act of 1938 mandated quality and identity standards, prohibited false therapeutic claims, and clarified the FDA’s control of product advertising, among other items. According to the Code of Federal Regulations (21 CFR 740.10a). Each cosmetic manufacturer is responsible for:

* using only safe and suitable ingredients
* substantiating the safety of those ingredients and of the finished product

FDA Cosmetic Regulation

This means that manufacturers of cosmetics in the United States, no matter how big or small, are obligated to perform safety tests on the products they produce. In fact, ingredients or finished goods whose safety has not been evaluated are misbranded (false, misleading, or fraudulent) and must have this text on the label:

“ Warning – the safety of this product has not been determined.”

The FDA can send warning letters, safety notices, and initiate recalls or withdrawals of product from the market. Safety testing is serious stuff!

Types of Safety Testing

The type of safety testing is often determined by area of contact (skin, eye area) and can be modified depending on the type of product and how it may be used e.g. diluted. Safety testing can also be used to generate product claims. Here are some examples:

* mildness
* hypoallergenic
* dermatologist tested

There are two commonly accepted methods for making skin safety assessments in the industry. These are the 21-Day Cumulative Irritation Test (CIT) and the Human Repeat Insult Patch Test (HRIPT). Both of these methods use a trained observer to measure inflammation, which is the body’s general response to distress. The four classic signs of inflammation are:

- Erythema (Redness)
- Edema (Swelling)
- Pain
- Heat

21-Day Cumulative Irritation Test

The CIT measures inflammatory response to an irritant. It occurs immediately and only at the site of exposure. The response tends to be universal (produces a reaction in most individuals) and depends on the strength and duration of exposure. In this type of test products are applied to human subjects under an occluded patch, usually on the back, and graded daily for a total of 21 days. A known irritant and a non-irritant are run as controls. The scores are summed across all subjects to provide a cumulative irritation score. The score can be compared to the large pool of historical test data to make judgments about irritation potential. An additional challenge phase can be run two weeks after the last patch was removed to understand potential for sensitization, which is usually measured with the HRIPT.

Human Repeat Insult Patch Test – Sensitization, Allergic Response

Sensitization is the process by which a person becomes, over time, increasingly allergic to a substance through repeated exposure to that substance. It is very different from irritation because it involves immune response, the reaction becomes worse with repeated exposure, and it is usually specific to individuals. The HRIPT consists of 2 phases, possibly 3.

Phase I is the Induction Phase where product is applied to the skin a few times during the course of a week. This is a followed by a two-week rest period after which the skin is exposed to the product again in Phase II or the Elicitation Phase.  A response in Phase II is usually allergic in nature and Phase III is used to verify and better define the reaction.

Photosensitzation

The HRIPT method can also be modified for photosensitization, which is particularly useful for sunscreens. Photosensitization can occur when normally harmless molecules undergo changes when exposed to UV light.

If you are a cosmetic chemist who works on hair care products, this conference would be a good one to attend. TRI Princeton is doing some great basic research on hair and hair products of anyone in the industry. See the press release below.
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TRI Princeton presents the 4th International Conference on Applied Hair Science
October 5-6, 2010
Princeton, New Jersey

TRI’s Conference on Applied Hair Science promises to provide a unique forum for the discussion of state-of-the-art science relevant to those practicing applied hair science. This year’s conference will inspire the hair care industry through an innovative selection of speakers from industry, academia and government.

Participants will have the opportunity to:

• learn from recognized leaders in hair science and technology presenting fundamental principals, an understanding of the evolution of current technology and contemporary experimental techniques
• interact with an international group of panelists, preseners and attendees to discuss category relevant topics in raw materials, claims and regulations
• experience demonstrations bringing the academic topics to the practical clarity of in-use observation

Key topics include:

Hair Care

*Mega trends in Naturals and Efficacy
*Multicultural Hair Solutions
*Performance Profiling
*Sensory Profiling & Consumer Perception

Actives and their Benefits

*Penetration of Fibers – Effects of Small Molecules on Hair
*Hair Growth
*Nutrition for Hair

Product Technology

*Silicone and Silicone Alternatives
*Deposition of Actives via Rinse-off Applications
*Hair Damage – Cutting-edge Technology, New Methods, Treatments
*Color Fading and Protection

Style – Devices and Formulations

*Curl Management/Treatment
*New Devices from light therapy to steaming irons
*How Devices are used on Hair
*Basic Research

Call For Papers

Abstracts for oral or poster presentations must be submitted by June 1, 2010. Please email your abstract to the Conference Organizer at info@triprinceton.org or complete the abstract submission form on the conference website. Proceedings of the Fourth International Conference on Applied Hair Science will be published as a special volume of a peer-reviewed journal.

For further information on the conference visit the TRI website.

Last fall I did a talk for the Joint Forensic Association meeting in Orlando. It was a lot of fun talking to forensic scientists about cosmetics. I did a modified version of my Beginning Cosmetic Chemistry course which focused less on formulating and more on the composition of cosmetics.

What I found most interesting was the way that forensic scientists use cosmetics as evidence in crimes.  Here are some examples.

Lipstick prints

You probably know forensic scientists use fingerprints for solving crimes, but did you know they can use lipstick prints and smears as well? By comparing the composition of a lipstick smear with that of a victim, forensic scientists can demonstrate indirect proof of contact or a relationship between victim and suspect. Also, it is sometimes possible to extract saliva DNA from the print. See this article published in the April 2002 issue of Forensic Science Communications a paper on how they do it.

Idea: Could lipstick manufacturers add an ingredient to their cosmetics that would help forensic scientists better identify prints?

Foundation smears

Like lipstick smears, make-up foundation can easily be transferred to clothing or other surfaces just through contact. Forensic scientists can discriminate between different types by using FTIR, SEM-EDX and GC-FID analysis. According to this paper in the Journal of Forensic Sciences, they can get up to 99.7% accuracy.

Idea: Could cosmetic scientists modify their formulas to help make identification even easier without impacting performance?

Shampoo identifications

Although it is thought to be a myth that your hair gets “used to” a certain shampoo, there is some evidence that components from your shampoo will accumulate in your hair. Using HPLC, forensic scientists have found that they can determine the type of shampoo that may have been used on a hair sample. The technique requires only a 5 to 10 cm single hair and is non-destructive.

This technique could be used for making cosmetic claims about your hair products

Hair bleach interference

Forensic scientists can use hair to determine whether a person has been taking illicit drugs. It’s really quite amazing what kind of things get trapped in your hair. They analyze samples using GC-MS and can detect codeine, morphine, cocaine, and opiates. Bleaching, perms and other hair treatments were found to significantly reduce the detectable amount of many of these compounds.

New ideas

While thinking about the intersection between forensics and cosmetic science, it occurred to me that this could be a rich area for new product ideas. The idea of putting something in your cosmetic formula to make it easier to identify seems like a pretty good one. In addition to helping law enforcement, it could also help stop product counterfeiters.

Think about your own products. How could you change them to make them more useful for forensic scientists?

One of my favorite parts of the C&T website is their “Biology Research” section. Here you’ll find science based articles that illuminate the latest understandings of basic human hair and skin biology.

An article that caught my interest was a summary of twins skin research published in the Archives of Dermatology. I was more of a hair care cosmetic chemist so I always find skin articles interesting.

Some facts I found most interesting.

It’s in your genes

Genetics is responsible for 60% of all aging. This will be noticed as fine wrinkles and skin growths. So, no matter what kind of special anti-aging cream a cosmetic formulator can create, it’s only going to affect 40% of the consumer’s problem. No wonder cosmetic chemists have such a hard time.

Smoking and eating

Smoking, being over-weight, and previous history of skin cancer were all correlated with higher levels of photodamage. Looks like more evidence that you should wear a UV protector.

Alcohol benefits

Drinking was correlated with lower photodamage scores. So, people who drink alcohol have better looking skin? I saw it hypothesized in a different article about this research that the alcohol may have come in the form of wine and the anti-oxidants in it could explain this result. The researchers didn’t separate out what type of alcoholic drinks subjects had so this remains a mystery.

How to have great skin

So, the advice I get from this research is as follows.

If you want great looking skin…

1. Don’t smoke
2. Don’t become overweight
3. Wear a sunscreen
4. Drink alcohol
5. Hope that you inherited youthful looking skin genes

Unfortunately, there is nothing in this research that indicates using anti-aging skin creams will give much benefit at all. Looks like the cosmetic chemists who work on these products still have more work to do.

This article on Gizmodo about the 10 Science stories that changed our decade made me think about the advances in cosmetic science that have changed our industry.

It’s pretty tough to narrow down but the following cosmetic science topics have certainly had a big impact.

1. Nanotechnology - Nanotechnology has been used in cosmetics since the early 1990s but it was only during the last decade that marketers caught on and started using it to sell products. The technology is promising but questions about safety have led to a backlash that could short circuit widespread use. Nanotechnology is currently used mostly in sunscreens. However, skin lotions, color cosmetics and hair products may all benefit from them in the future.

2. Green formulations. Little has affected cosmetic formulation in the last decade than the Green Movement. Proponents of this philosophy have prompted personal care manufacturers to completely reformulate many products to remove animal derived ingredients, add organic extracts and expunge formulas of any chemical that might sound controversial. Formulas also have to be sustainable and come from fair trade sources. The Sustainable Cosmetics Summit goes through all the things a cosmetic chemist will need to know to formulate “green” in the future.

3. REACH - One of the most impactful pieces of regulation that has come to the cosmetic industry, REACH is the EU’s directive to get the chemical industry to prove the safety of their ingredients. This means that formulation chemists everywhere will have to think through the global compatibility of all ingredients. The practical implication is that your raw material suppliers will probably open factories in Europe so they can get around many of the toughest requirements.

4. Alternative preservatives. Parabens and formaldehyde donors were fine in the 90′s but in the last decade, they were some of the most vilified chemicals a cosmetic formulator could use. Raw material suppliers have been trying to come up with alternatives but the truth is, nothing yet matches the current preservatives for efficacy, safety, and cost. Finding alternative preservatives that satisfies the chemically frightened consumers is the Holy Grail.

5. Globalization – It used to be that you could create a formula for your market and if it sold well, you would launch it into other countries. But with new regulations and a more global focus, companies are beginning with a global mindset. In the last decade, formulation chemists had to think about all of the potential markets of their products before anything was launched. This prevented a huge reformulation effort when the company inevitably wanted to launch in new countries. No doubt, this trend will continue.

6. Animal testing alternatives – The last decade saw a huge push to get rid of all animal testing of cosmetics. Consumers don’t like and neither do cosmetic companies. Scientists have worked hard to come up with alternatives but the work isn’t complete and is proving harder than once believed. The EU is due to ban all animal testing by 2013. For the innovative cosmetic formulator, this could become a major challenge.

7. 55% VOCs – It started in the 1990′s but in the last decade, cosmetic companies had to completely revamp most formulas to comply with VOC regulations (Volatile Organic Compounds). The 55% VOC limit set on hairsprays was a significant challenge the radically changed the performance of most products. Since the cosmetic industry is a much easier target than the auto industry, there is no doubt these regulations will continue to make things difficult for formulation chemists. Fortunately, we’re up to the challenge.

8. New Sunscreens – The FDA has yet to issue a final sunscreen monograph but that hasn’t stopped raw material suppliers from working on new ones. Significant strides have been made in the last decade to create UVA blocking sunscreens. The launch of Mexoryl was the first new sunscreen available in decades.

9. Genomics - This is the study of the genetics of an organism and during the last decade, cosmetic companies used information from the Human Genome Project to create new products. Some marketing companies have jumped on the bandwagon and gotten ahead of the science by offering unproven DNA-matched cosmetics. These products are just marketing hype but personal care giant Procter and Gamble have actually used genomics to identify potentially game changing active ingredients for skin.

10. Open Innovation – Innovation was all the rage in the last decade. Perhaps the most interesting new route to innovative cosmetics was the concept of Open Innovation as illustrated by companies like Innocentive and 9 Sigma. These web-based companies provide a way to link up independent inventors with big companies to help launch products. This could be the wave of the future for the cosmetic industry and something that every cosmetic scientist should know about.

What do you think were the top stories in cosmetic science over the last decade? Leave a comment below.

Here’s an interesting bit of research that might change the way cosmetic chemists make cosmetics and personal care products in the future. We know that surfactants plus heat & mixing are used for making oil and water emulsions, but in the future shaking might also be used.

Writing in the journal Chaos (yes there is such a thing), researchers did an experiment that showed how water and oil mix. It turned out that by bouncing an oil-coated water droplet, a tiny emulsion could be formed inside the water droplet. See the video for a demonstration of what the researchers did.

What is interesting about this is that it was silicone oil that was used. Silicone is sometimes difficult to formulate with because it is not compatible with most traditional cosmetic emulsifiers.

I’m not sure if this manufacturing trick will ever be used on a large scale for cosmetic manufacture, but it is an interesting approach. It could lead to a more efficient way to create cosmetics which uses less energy. It may even lead to lower concentrations of surfactants required which is beneficial because surfactants are often the most irritating components of a cosmetic formula.  It’s great to see this basic research advancement in cosmetic science.

If you haven’t done so yet, you might want to review part 1 of this surfactant series to learn what surfactants are and when you might use them.

There are thousands of different types of surfactants and it can be difficult to know which to use for any specific application. This task is made easier by knowing how surfactants are classified.

Types of surfactants

Surfactants can be grouped by the charge characteristic of their polar (hydrophilic) head groups. The four groups include

Anionic
Cationic
Amphoteric
Non-Ionic

We’ll discuss each of these next.

Anionic Surfactants

Anionic surfactants are those that have a negative charge on their polar head group. They include groups like carboxylic acids, sulfates, sulfonic acids, and phosphoric acid derivatives, of which the first three are most important in cosmetics. They are most useful for applications that require good cleansing and foam.

Carboxylic acid anionic surfactants like stearic acid are useful for creating stick products like deodorants and antiperspirants. The salt version (sodium stearate) makes an excellent soap.

Sulfates are the next most commonly used anionics. They include synthetic detergents like sodium lauryl sulfate (SLS), ammonium lauryl sulfate (ALS), or their ethoxylated companions, sodium laureth sulfate (SLES). They are excellent foamers, cleansing agents, and are relatively inexpensive. The drawback is that they can be irritating and some consumers find them troubling. In fact, sulfates are some of the most highly vilified cosmetic raw materials but we’ll save that discussion for another time.

Sulfonic acid surfactants are generally more mild than sulfates. They include Taurates (derived from taurine), Isethionates (derived from isethionic acid), Olefin sulfonates, and Sulfosuccinates. The reason they are not used more often is that they are more expensive to produce and do not provide a significant enough benefit over Sulfates.

Cationic Surfactants

Cationic surfactants are those that have a positive charge on their polar head group. They are most useful for conditioning cosmetics. They include chemical classes such as Amines, Alkylimidazolines, Alkoxylated Amines, and Quaternized Ammonium Compounds (or Quats).

By far the most significant cationic surfactants used in cosmetics are Quats. These are nitrogen-containing compounds that acquire a positive charge when dispersed in solution. This positive charge makes them electrostatically attracted to the negative (damaged) sites on hair and skin protein which makes them resist rinse-off. Quats like Cetrimonium chloride and Stearalkonium Chloride provide the basis for numerous hair conditioners.

The biggest challenge of working with cationics is that they are not typically compatible with anionic surfactants. This means it is difficult to produce products that simultaneously clean and condition using only surfactants. Cationic surfactants can also be irritating so this must be considered when formulating cosmetics with them.

Amphoteric surfactants

Some surfactants have the potential to have both positive and negative charges depending on the environment they are placed. This characteristic is termed “zwitterionic” and surfactants of this type are called amphoterics. Examples include Sodium Lauriminodipropionate and Disodium Lauroamphodiacetate.

Amphoterics are primarily used in cosmetics as secondary surfactants. They can help boost foam, improve conditioning and even reduce irritation. They are also used for baby shampoos and other cleansing products that require mildness. The drawbacks are that they do not have good cleansing properties and don’t function well as emulsifiers.

Non ionic Surfactants

The last class of surfactants we’ll cover are the ones that contain no specific charge. These are termed non-ionic surfactants and are used most often as emulsifiers, conditioning ingredients, and solubilizing agents. There is no other type of surfactant that is used more frequently than nonionic surfactants. The primary nonionics used for cosmetics include alcohols, alkanolamides, esters, and amine oxides.

Alcohols such as Cetyl or Stearyl alcohol are used in creams and lotions to provide body and feel to the formulas. They also help stabilize the emulsions and can reduce irritation. Amine oxides like Cocamidopropylamine oxide are used to boost foam in cleansing products. A number of esters are used to provide conditioning, slip and shine to biological surfaces. Polysorbate esters are also excellent solubilizing ingredients for fragrances and other botanical oils.

Surfactants and Cosmetic Chemists

Most of your formulating time will be spent working with different levels of surfactants and trying to pick out just the right one for your application. This brief overview provides all the basics that you need to know to get started (and to impress Marketing people with your knowledge), but it is only the start. You need to work with surfactants, talk with your surfactant suppliers and experiment with different blends. Only then will you get a better understanding of these molecules and what you can do with them.

For further reading see the surfactant chapters in the following industry books
Beginning Cosmetic Chemistry 3rd Edition

Harry’s Cosmeticology

Chemistry And Manufacture Of Cosmetics Ingredients 2 Book Set

Do you have more questions about surfactants? Leave a comment below.