New Hair Color Chemistry Engine Improves Hair Fiber Quality

New Hair Color Chemistry Engine Improves Hair Fiber 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 AminoGlycine.  Amino glycine changes the rules of hair coloring and delivers great color with less hair damage.

Re-assessing the Color Process

In 1999, a small team of P&G researchers were challenged to develop a hair color system that that would be less damaging without compromising hair color results.  The team began to develop new chemistry that worked at lower pH but could still effectively lighten the hair. Current permanent color today uses a combination of hydrogen peroxide

Hydrogen peroxide is by far the most frequently used oxidant in oxidative haircolor products. The reactive species formed in situ from hydrogen peroxide and ammonia is the hydroxyl anion, which is responsible for bleaching the existing hair color and forming the new wash resistant color complexes.

, ammonia, and 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

The hydroxyl (HO*) radical is an undesired hair color by-product of a reaction between hydrogen peroxide and metal ions (such as copper) which are present in tap water and also hair. The radical can interfere with the color formation process and contributes to fiber damage. Chelants such as EDDS can be added to hair colorants to prevent the radical formation by complexing the metal ions.

, an undesired by-product of the peroxide bleaching system. 

Controlling Radicals is the Key

"Our new amino glycine technology features a combination of ammonium carbonate

Used in combination with hydrogen peroxide as an alternative to the conventional ammonia / peroxide bleach engine in permanent colorants. Oxidizes melanin and dye precursors with greater efficieny. The active species formed in situ is peroxymonocarbonate.

, 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 AminoGlycine's higher selectivity for melanin, the hair pigment, versus keratin, a strong protein in the hair follicle that would incur damage without this selectivity.

Radicals Across Disciplines

The mitigation of radical formation in a lightening system has other 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."

Marsh J, Gummer C, Dahlgren M. Novel Permanent Hair Coloring Systems Delivering Color with Reduced Fiber Damage, Journal of Cosmetic Science, Vol. 58, No. 1, January/February, 2007.