Writing in its international patent filing, Unilever outlined a novel use of trehalose in a formulation that promoted scalp health, more specifically as a prebiotic to inhibit the fungus Malassezia restricta typically found at higher levels in cases of dandruff. The composition, it said, could be used in a range of leave-on or rinse-off products, including hair creams, hair serums, foams and even shampoos.
‘Effectively’ treating the common scalp disorder dandruff
The personal care major said that were already several prebiotic topical skin care compositions designed to interact with existing microorganisms on the body’s surface – many created by other major beauty players. However, there remained a clear need for a composition that targeted scalp care, more specifically dandruff, it said.
“[Dandruff] is a common scalp disorder affecting many people with the symptoms of shedding, itching and visible flakes on the scalp,” Unilever wrote in its patent filing.
And in dandruff cases, levels of the fungus Malassezia restricta were “significantly higher” compared to a healthy scalp, it said, so reducing the levels of this fungus was considered “one of the effective approaches to effectively treat dandruff”.
Unilever’s patent outlined one such method to achieve this – using the disaccharide threhalose as a prebiotic that interacted with Staphylococcus hominis naturally present on the scalp’s surface to inhibit ailment-inducing microorganisms, in this case Malassezia restricta [M. restricta].
“We have found that disaccharides, preferably trehalose, is effective against M. restricta as [a] prebiotic and thereby inhibits dandruff to promote scalp health,” the company wrote.
Unilever previously filed a separate international patent on a rinse-off shampoo it said also targeted dandruff by reducing the level of Malassezia restricta on the scalp. Filed in 2020, that formulation used a combination of the well-known anti-fungal agent piroctone olamine and coconut oil.
Beyond scalp care – deodorants, sunscreens and wipes
Unilever said use of the disaccharide as a prebiotic also offered promise beyond scalp care, for topical beauty products targeting other ailment-inducing microorganisms, most notably Staphylococcus aureus that was associated with various adverse effects on skin health. Beauty formulation opportunities included deodorants, lipsticks, mascara, sunscreen lotions, skin lotions and even body wipes.
“Trehalose, in the presence of S. hominis, is effective against the ailment inducing microorganisms like Malassezia restricts and Staphylococcus aureus,” Unilever said. “Therefore, it is clear (…) that trehalose can effectively be used as a prebiotic for inhibiting ailment-inducing microorganisms when applied on an external surface of a human body.”
The company previously filed a separate international patent in 2020 on a ‘microbiome balancing’ topical formula that used saccharide isomerate as a prebiotic. This formula, it said, could also be used in a range of products, including deodorants, hand sanitisers, body lotions and sprays and even toothpaste.
In its latest patent filing, Unilever said the topical composition preferably contained trehalose at 0.1 – 5% by weight of the composition, no matter what product formulation it was used in. For leave-on formulations, the topical was preferably an emulsion and for rinse-off formulations, an acceptable surfactant base was required.
Unilever outlined specific formulation requirements for use in deodorants and sunscreens in its patent.
Source: WIPO International Patent No. WO/2022/008163
Filed on: June 11, 2021. Published on: January 12, 2022.
Title: “Use of trehalose as prebiotic for inhibiting ailment inducing microorganisms”
Inventor: Unilever – CC. Chu, M. Pu, Q. Yin and X. Yue