To see one example in action, Silverson visited Holiferm’s R&D laboratory in Manchester, where the team formulates personal care products around their own naturally derived biosurfactants, sophorolipids.
During the visit, Silverson and Holiferm explored how sophorolipid biosurfactants and high shear mixing technology can work together to address one of the category’s most complex formulation challenges: creating a smooth, stable and consumer-ready natural toothpaste. The move towards ‘clean’ ingredients is no longer limited to skincare or haircare. Oral care formulators are now also responding to consumer demand for formulations that feel more natural, transparent, and environmental conscious, whilst still delivering the familiar sensory and functional performance expected from ‘typical’ everyday products such as toothpaste.
Holiferm-produced sophorolipids are derived through fermentation rather than petrochemical synthesis, making them an ideal choice for this application. In the video highlighting the use of these ingredients (available on the Silverson website), Application Scientist Clarissa Clark walks Silverson Technical Sales Engineer James Cardus through a full natural toothpaste formulation using sophorolipids as the primary active surfactant system.
As Clarissa explains, sophorolipid use in oral care can help:
- Support anti-biofilm performance, helping prevent bacteria from clinging to the tooth surface
- Solubilise active ingredients such as peppermint oil
- Contribute to the foaming effect consumers expect from toothpastes
Toothpaste formulations are among the more demanding mixing tasks in personal care. It is not a simple liquid blend, but rather a high-viscosity solid suspension with complex rheology, making it difficult to process using conventional mixing methods.
During the demonstration, Clarissa starts with the liquid ingredients, then begins adding the powders that need to dissolve. Early on, that means using humectants like sorbitol and xylitol, a stage at which the Silverson Laboratory Mixer noticeably speeds up the process and reduces overall batch time.
“I love the Silverson for this application because, as always, it’s saving me a whole bunch of time.” — Clarissa Clark, Application Scientist, Holiferm
Then comes the hardest stage: incorporating the silica. Silica is essential for cleaning and texture, but it’s difficult to disperse. It agglomerates readily, and conventional mixers tend to move those clumps around the vessel rather than break them down. The high shear action of the rotor/stator workhead draws material in, breaks the agglomerates apart, and distributes the silica evenly throughout the batch.
Silica agglomerates vs. smooth, finished paste produced with a Silverson High Shear Mixer
“Silica generally stays in these clumps in the formulation,” Clarissa explains, “but on the Silverson, it sends it right through, smooths it out, and the toothpaste is ready to go so much quicker.”— Clarissa Clark, Application Scientist
For high-viscosity products like toothpaste, aeration can also be a major problem. Once air is incorporated, it can be difficult to remove and affects the appearance, filling, stability, and final product quality.
The Silverson Lab Mixer helps minimise aeration by drawing product up from the bottom of the container rather than pulling large amounts of air down from the surface. As James notes towards the end of the demonstration:
“It’s amazing, there’s no aeration at all, really...formulations like that that are very viscous would hold on to a lot of air, and it’s just part of how that mixer picks up from the bottom of the container and avoids pulling in huge amounts of air from the surface.” — James Cardus, Technical Sales Engineer
A special thank you to Clarissa and the Holiferm team for welcoming Silverson into their R&D laboratory and sharing their expertise in biosurfactant formulation.
To find out more, visit the Silverson website: www.silverson.com
