SCIENCE NEWS FROM P&G BEAUTY VOL. XIII 2007

New Color Chemistry improves hair Quality

For the millions of men and women around the world who color their hair, fiber damage is a significant concern. P&G Beauty has confronted this problem head on with the first major chemistry innovation in nearly 50 years, a new hair color chemistry called amino glycine technology. This new color chemistry changes the rules of hair coloring and delivers great color with less fiber damage.

Re-assessing the Color Process

In 1999, a small team of P&G researchers were challenged to develop a hair color system that would be less damaging without compromising hair color results. The team began to develop new chemistry that worked at a lower pH, but could still effectively lighten the hair. Current permanent color uses a combination of hydrogen peroxide, ammonia and a high pH, which removes up to 99 percent of the protective, lubricious f-layer of the hair's surface. This causes irreversible physiochemical changes that result in dryness, dullness and increased susceptibility to mechanical stress. The majority of this damage is caused by a very high pH (10-11) and the HO* radical, an undesired by-product of the peroxide lightening system.

Controlling Radicals Is the Key

"Our new amino glycine technology features a combination of ammonium carbonate, peroxide and glycine. It not only reduces pH but also helps minimize undesirable free radical production," said Jennifer Marsh, PhD, Principal Scientist, P&G Beauty and Technology Division. "This process is actually quite different from current color technology. We have harnessed the power of the new lightening system to more efficiently lighten and color hair, while the addition of the amino acid glycine helps mitigate radical formation. As a result, the damage caused to the hair fibers is dramatically reduced." The combination allows scientists to reduce damaging radicals and color hair using a pH level of 9, compared to a standard pH of 10-11. Hair fiber damage is further minimized due to the amino glycine technology's higher selectivity for melanin, the hair pigment, versus keratin, a strong protein in the hair follicle that would incur damage without this selectivity.

Old chemistry vs. Amino glycine technology

Radicals Across Disciplines

The mitigation of radical formation in a lightening system has important implications in the field of science outside of hair care. Harmful radicals attack and damage DNA, proteins (collagen, elastin, keratin) and moisture barrier lipids and contribute to aging and decomposition of cells.These radicals can be fought by using antioxidants.

"This has been a prominent issue across various areas of research, including applications not only in skin care and hair care, but also in ozone damage and medical research," stated Dr. Marsh. "You can't have oxidant chemistry without radicals somewhere along the way. Any type of radical research is fundamental research to understand the mechanisms at work. We hope this research will help further improve the progress being made in this arena by looking at unique ways that radicals can be managed."

New Colorants Bring Natural Look to Foundation

Providing coverage of imperfections while maintaining the look of naturally flawless skin is an enduring need of women who use color cosmetic foundations. Until recently, however, the ability of scientists to deliver this benefit has been limited by the colorants available for use in foundation formulations. "The drawback comes when, in the process of hiding imperfections, women can also remove skin's positive color variation and inadvertently create a less natural, monochromatic appearance," said Sarah Vickery, PhD, Senior Scientist at P&G Beauty.

To address this trade-off, researchers at P&G Beauty have worked to create new possibilities for delivering natural, lifelike color to the skin via new colorants specifically designed to increase foundation vibrancy and chroma variation, while maintaining the hue and lightness range of human skin tones.

High-Chroma Colorants Deliver Vibrancy with Sheer Finish

Due to the high-refractive index and small particle size of traditional inorganic pigments, shades can appear overly opaque and monochromatic. By using high-chroma organic colorants of a specific refractive index and size range in combination with the traditional inorganic pigments, P&G Beauty scientists can provide sufficient coverage of imperfections with desired vibrancy while delivering a sheer finish that more closely mimics that of naturally flawless skin.

Encapsulated Colorants Match Skin Surface Energy for Natural Appearance

The challenge with water-soluble highchroma colorants, which are used in lipsticks and other cosmetics, is that the dyes tend to stain skin as they come into contact with the water in the stratum corneum. To circumvent this concern, P&G Beauty partnered with Ciba Specialty Chemicals to create a novel organic colorant encapsulation technology, which creates a stable, non-bleeding polymeric shell around the colorants. This allowed researchers to exploit the high-chroma benefits of these colorants, without the drawbacks.

With surface energy optimization, foundation pigment is distributed evenly. With traditional
foundation, pigment is clumped in areas of depression and wrinkles.

Additionally, scientists found that the surface energy of components of skin compared to the new encapsulated organic pigments were extremely well-matched. "We looked at a range of particles and molecules to create a chemistry that is a better match for skin," said P&G Beauty scientist Steve Page. "The encapsulated material mimics skin very closely." Optimizing the surface energy to skin results in a more even distribution of the colorants across the face, resulting in a more natural appearance.

"This research demonstrated how in-depth color understanding and biochemistry can provide innovative solutions for the cosmetic industry and, in this case, meet a major consumer need," said Vickery.

Myths & Facts

Anti-dandruff shampoos cause hair color to fade faster. MYTH - Studies on successive washing of color-treated hair with a pyrithione zinc shampoo (the most effective dandruff treatment to date) show no difference from a cosmetic shampoo or even regular tap water.
Some shades of hair color fade faster than others. FACT - Red shades tend to fade the fastest because of their relatively small molecule size, which can diffuse from the hair and wash away more quickly than other shades. UV exposure also breaks down the red tone more easily, while pure browns and blacks resist fading because their color molecules tend to be larger. Blonde shades have little color, so fading is less of a concern.

Strangely Beautiful

P&G Beauty and P&G's Global Biotechnology division are on the cusp of the next frontier of beauty and health research-the development of cell-based in vitro models. Cell model systems help researchers understand the basic biological interactions between cells and offer a safe and inexpensive alternative for testing the safety and efficacy of new ingredients.

Monolayer culture of hair follicle keratinocytes

While several effective skin cell culture models exist, cell culture models for hair are limited. But P&G Beauty is working on a potentially novel model involving hair follicle keratinocytes. The striking image at right is a monolayer culture of these keratinocytes, which are the cells in the hair follicle that create the structure of the hair shaft. They are responsible for hair strength, damage resistance, shine and softness. This culture will be used to help understand the role keratinocytes play in beautifying the hair and how they differ from keratinocytes in the skin. Additionally, the culture may be used to test the safety of ingredients used in shampoos, conditioners and styling products.

Lab Notes

Niacinamide Shown to Increase Tolerance and Effectiveness of Topical Retinoid Therapy

While retinoid (vitamin a) therapies are among the most effective topical anti-aging treatments available, they can irritate or damage the skin's barrier and therefore are not fully utilized. P&G Beauty scientists found that if the skin's barrier could be strengthened, retinoid treatments could be more widely utilized. In a recently published paper (Draelos et al Cutis 2066;78:275-281) P&G Beauty reports results showing that the addition of niacinamide-containing moisturizer (which has barrier-building properties) to tretinoin (concentration of .025 percent) therapy improves anti-aging results and patient tolerance.

Use of a niacinamide containing moisturizer (Moisturizer A) reduces irritation associated with topical retinoid (0.025% tretinoin) treatment

In the 10-week randomized, split-face clinical trial, 40 female subjects applied blind-coded moisturizers with and without niacinamide for a 2-week preconditioning period and during an 8-week retinoid treatment period. Significant improvements in investigator-assessed skin texture were observed, including a reduced appearance of fine lines after the treatment period (p<0.01) for the niacinamide leg vs. the control. Additionally noted was reduced skin dryness and irritation in the niacinamide study leg (p<0.05).

Fast Forward

Hyperpigmentation Breakthrough

Women around the world may soon no longer have to trade-off effective age spot lightening for skin irritation and discomfort. Previously, many of the most effective skin lightening agents have caused irritation and occasionally skin discoloration. A new ingredient, undecylenoyl phenylalanine, is promising a safe alternative for improved appearance of hyperpigmented skin.

In vitro testing shows that undecylenoyl phenylalanine works differently than other topical ingredients for spot reduction. Currently, niacinamide and N-acetyl glucosamine work by interrupting the melanin synthesis pathway. Undecylenoyl phenylalanine works as an MSH (melanin stimulating hormone) antagonist, preventing the melanin synthesis from starting. In vitro testing shows that the combination of undecylenoyl phenylalanine, N-acetyl glucosamine and niacinamide show an additive effect in reducing melanin production without damaging skin cultures.

Uneven distribution of melanin manifests itself as age spots and hyperpigmentation. Undecylenoyl phenylalanine promises to safely treat hyperpigmentation by preventing the melanin synthesis from starting.

In the Spotlight

For decades, P&G Beauty scientists have utilized innovative technologies to research new generations of clinically advanced formulas that will deliver the highest quality skin and hair care products.

Dr. Marsh joined P&G Beauty in 1993 after receiving her PhD from Oxford University

Hair color expert Dr. Jennifer Marsh is an accomplished Principal Scientist in the Beauty and Technology division. Dr. Marsh has conducted multiple research studies specializing in bleach and oxidative chemistry and hair color technology.

One of Dr. Marsh's most recent achievements is her leadership on a new hair color chemistry advancement, which was the result of several years of collaboration by a team of P&G Beauty's scientists.

As a result of Dr. Marsh's novel research, she has earned recognition from prestigious scientific organizations, including an American Society of Cosmetics Chemists award for her research on Chelant EDDS Technology and an honor for best conference paper from Princeton for her work on High Pressure Differential Scanning Calorimetry.

P&G BEAUTY SCIENCE

P&G Beauty Science has more than 1,800 scientists and technical employees working at 11 global technical centers with an unparalleled commitment to technology development. Company scientific efforts have resulted in over 3,500 active beauty care patents. This allows P&G to develop products uniquely suited for different types of hair and skin, and tailored to different cultures and climates.

P&G Beauty products help make beauty dreams real and grooming enjoyable every day for millions of women and men worldwide. With more than 100 brands available in nearly 130 countries, P&G Beauty delivered sales of more than $22 billion in fiscal year 2006/07, making it a leading global beauty company. P&G Beauty brands include: Pantene^®, Olay^®, Head & Shoulders^®, Max Factor^®, Cover Girl^®, Rejoice^®, Herbal Essences^®, Koleston^®, Clairol^®, Gillette^®, Sk-II^®, Wella^®, Joy^® by Jean Patou, Hugo Boss^® and Lacoste^®. (NYSE: PG)

CONTACT INFORMATION

To talk to a P&G scientist or to learn more about ongoing research at P&G Beauty, contact:

Heather Cunningham P&G Beauty Science 513-626-2606