The smallest of the alpha hydroxyl acids (AHAs), glycolic acid has been included for many years in anti-aging and other skin care products; but, according to DuPont its potential in the personal care field does not stop there.
Although it has appeared in a limited number of hair care products, particularly those launched in the Asian markets, relatively little has been known about the effect of glycolic acid on the hair.
Research Fellow at DuPont Bob Burch, explained that the company embarked on the research in an attempt to understand why the ingredient was being incorporated in certain products.
“We wanted to know why people were using it. If we could understand the basis for it, we felt it could open up new opportunities for the ingredient,” he told CosmeticsDesign.com.
The company performed a number of tests to investigate the effect of it cosmetics grade glycolic acid ingredient GlyPure on the hair, including the stability of the keratin and the ability of the hair to withstand repeated wet and dry combing.
Improves stability of keratin
The Differential Scanning Calorimetry Experiment (DSC) was performed to determine the temperatures at which water separates from the keratin, which Burch explained is a way of judging the stability of the keratin.
According to DuPont’s research, healthy hair treated with GlyPure can withstand temperatures of up to 6.5 degrees centigrade higher than hair treated with stearyl alcohol and water, which was used as a control. Bleached hair treated with GlyPure withstood temperatures 2.5 degrees higher than with the control.
Burch claimed these results show that treatment with GlyPure results in a more stable form of keratin.
In addition, the company found that hair treated with a conditioning treatment based on GlyPure sustained fewer broken fibres after repeated brushing than hair treated with one of two conditioning products currently available on the market, or untreated hair.
Wet combing experiments found similar results, with the GlyPure-containing conditioning treatment performing better than conditioner without GlyPure and the untreated control.
The mechanism behind the effect of the glycolic acid on the hair shaft is not fully understood; however, Burch explained that - unlike many other hair conditioning ingredients that do their job on the surface of the hair - glycolic acid actually penetrates the hair shaft and reacts with the keratin.
Moisturising on the scalp
DuPont also claims the ingredient may have moisturising benefits for the scalp, reducing flakiness and dryness.
The company hopes that the recognition glycolic acid and AHAs have in the skincare market will help bring success in the hair care segment.
“The familiarity people have for the ingredient from skin care is part of the picture and will play a role in its success as a new tool in the formulator’s tool kit,” Burch said.
Currently, DuPont has only looked at the effect of glycolic acid on Caucasian hair samples, but work on different hair types is underway and will be published shortly.
In addition, different end points will be investigated such as color management and shine and lustre.