A research team in China has found that waste from the Himalayan Prinsepia utilis Royle oilseed plant can be repurposed as a stabiliser for use in cosmetic applications, Cosmetics Design Asia wrote.
A deciduous shrub that thrives at high altitudes in the Himalayan region, Prinsepia utilis Royle has widely been utilised in Chinese and Indian folk medicines to treat ailments such as skin diseases, rheumatic pain and and inflammation, while its oil can be used for cooking or to make laundry soap.
However, the oil extraction process typically leaves behind a substantial amount of solid residue, which has previously been discarded as agricultural waste, according to the 11 February report.
In their paper first published by MDPI on 9 October 2025, researchers from Yunnan Characteristic Plant Extraction Laboratory, Shanghai Jiyan Bio-Pharmaceutical Development and East China University of Science and Technology demonstrated that this waste contained functional compounds.
The scientists converted the raw seed residue via micronisation technology into a fine, spherical powder capable of stabilising a Pickering solution, a type of emulsion that is stabilised by solid particles creating a physical barrier at the interface between the oil and water phases, reducing the need for additives.
This was in contrast to traditional creams, which often used synthetic surfactants to prevent oil and water from separating, which could cause skin irritation or environmental concerns.
The powder’s effectiveness depended heavily on its particle size.
During the study, a ball mill was used to reduce the raw residue from an average size of approximately 61 microns to 20 microns.
The smaller, spherical particles dispersed more quickly to the oil-water interface, where they formed a dense, protective film around oil droplets, the researchers found.
The team noted that the spherical shape of the particles could be beneficial in cosmetic applications, as it would provide a smooth feeling on the skin.
As the process used in the study used mechanical grinding rather than chemical modification, the resulting ingredient remained entirely natural and maintained the parent plant’s inherent biological benefits, the report said.
To determine how the powder would perform in real-world formulations, the team tested its ability to stabilise five different types of cosmetic oils, ranging from non-polar mineral oils to highly polar ethers.
The results showed that the micronised seed powder performed best with non-polar oils like squalane and mineral oil. In those mixtures, the powder formed stable oil-in-water emulsions that remained uniform for 28 days.
When examined under a microscope, the researchers noted that as well as coating the oil droplets, the particles formed a three-dimensional network throughout the water phase, providing a mechanical barrier that could prevent the product from separating over time.
In addition to its role as a stabiliser, the researchers discovered that the Prinsepia utilis Royle powder was naturally rich in polyphenols and polysaccharides, which provided an antioxidant function.
When testing the powder’s ability to scavenge free radicals, the team found that the emulsion’s antioxidant capacity increased in relation to the concentration of the seed powder.
At a concentration of 3%, the powder achieved a free radical scavenging rate of over 91%.
“Its ability to provide long-term stability while delivering high levels of antioxidant protection could make it an alternative to synthetic stabilisers,” the researchers were quoted as saying.
Looking ahead, the research team planned to explore how the micronised seed powder performed in more complex, ready-to-market formulations, Cosmetic Design Asia wrote.
While the current study focused on simple oil-and-water mixtures, future tests would involve the addition of common cosmetic additives, such as preservatives and fragrances, to ensure the stabiliser remained effective in a commercial environment.
The team also said they were interested in applying the powder to products designed for sensitive skin.
