Curl power: Kao Corp uses carbonated water to improve active shampoo

Presenting study findings at the 2022 IFSCC Congress in London, UK, the company said it had undertaken research to improve active ingredient penetration of the internal hair shaft and hair fibres in a bid to improve efficacy of its hair care formulas.

Noriyuki Tanji, scientist for hair care products research at Kao Corporation, said penetration was an “important factor”​ to consider when developing and improving active hair care formulas.

Hair penetration sometimes needs ‘enhancement’ tech​

“There will not be an effect if [active ingredients] do not penetrate the hair fibre efficiently. Therefore, a penetration enhancement is required,”​ Tanji told attendees during his presentation at the Congress.

However, he said common penetration enhancements typically led to high pH levels in the formula which could cause hair damage – something the company wanted to avoid, particularly when designing products for curly or ‘unruly’ hair.

“Styling unruly hair can be a challenge. Many customers who struggle with unruly hair use styling products or chemical hair straightening. However, [this] requires a long styling time and causes hair damage.”​

Kao Corp had already developed a curl-loosening technology using p-Toluene Sulfonate (PTS) to loosen hair fibres without force, he said, improving curl alignment and making post-wash styling easier. But, Tanji said this technology took around four hours to achieve a 20% improvement, which was too long for an effective hair care product.

It was for this reason, he said, that Kao Corp had developed a “new penetration enhancement technology” ​that could operate under mild conditions – carbonated water.

H20 power reaches the macrofibrils ​

Carbonated water had already been widely studied for its promotion of blood flow and ability to normalise keratinisation, Tanji said. But it had also been reported to enhanced absorption, he said, prompting Kao to take a closer look at the ingredient and study its potential in hair care formulas.

Findings from the company’s research showed that when carbonated water was integrated into a hair care formula, penetration of the PTS curl-loosening technology improved in both aqueous solutions and shampoos.

When assessing the mechanism of action more closely, Tanji said the team had initially believed the carbonated water acted as a penetration enhancer for PTS, but findings showed otherwise. Carbonated water “did not clearly increase”​ PTS penetration, he said, instead it appeared to work within the macrofibrils of the hair cortex – the structural part of curly hair that swelled when in contact with PTS.

Tensile stress testing had shown that the carbonated water “reaches the structures in the macrofibrils and renders the structure flexible”​, he said.

“…These findings indicate carbonated water facilitates the impact of PTS in the macrofibrils leading to penetration enhancement in nanoscopic regions.”​

‘Stress-free styling’ for curly hair consumers​

The shampoo containing PTS and carbonated water, therefore, introduced “stress-free styling”​ potential at the hair washing stage, which was less time-consuming and less damaging for consumers, Tanji said.

“We reduced a significant barrier, especially for customers who struggle with unruly hair​

“…We expect to revolutionise our products, and carbonated water also has the potential to be used widely to improve the performance of various hair care ingredients. We would like to do further research in the future,”​ Tanji said.

The CEO of Kao Corporation recently said there was an immediate need to revitalise its hair care business​ amidst stiff competition in the mass market sector.