Lab tests show that new material provides relief from dry mouth

A novel aqueous lubricant technology designed to help people living with xerostomia (dry mouth) is between four and five times more effective than commercially available products, lab tests have found.

A potato protein - coloured dark green - forms the mesh-like architecture of the hydrated microgel, partially coated by a hydrogel made by a polysaccharide xanthan gum, shown in light green
A potato protein - coloured dark green - forms the mesh-like architecture of the hydrated microgel, partially coated by a hydrogel made by a polysaccharide xanthan gum, shown in light green - Dr Anna Tanczos

Developed at Leeds University, the saliva substitute is described as comparable to natural saliva in the way it hydrates the mouth and acts as a lubricant.

Under a microscope, the molecules in the microgel appear as a lattice-like network or sponge which bind onto the surface of the mouth. Surrounding the microgel is a polysaccharide-based hydrogel which traps water. According to the university, this dual function will keep the mouth feeling hydrated for longer. 

In a statement, project lead Professor Anwesha Sarkar said: “Our laboratory benchmarking reveals that this substance will have a longer-lasting effect.  

“The problem with many of the existing commercial products is they are only effective for short periods because they do not bind to the surface of the mouth, with people having to frequently reapply the substance, sometimes while they are talking or as they eat. That affects people’s quality of life.” 

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Results from the laboratory evaluation - “Benchmarking of a microgel-reinforced hydrogel-based aqueous lubricant against commercial saliva substitutes” - are reported in Scientific Reports

The novel microgel comes in two forms: one made with a dairy protein and a vegan version using a potato protein.  The performance of the newly developed substance compared to existing products is due to adsorption.

The new substance was benchmarked against eight commercially available saliva substitutes including Boots own brand product - Biotene; Oralieve; Saliveze; and Glandosane. The benchmarking was done in a laboratory on an artificial tongue-like surface and did not involve human subjects. 

The testing revealed the Leeds product had a lower level of desorption; with the commercially available products between 23 and 58 per cent of the lubricant was lost. With the saliva substitute, the figure was seven per cent, with the dairy version slightly outperforming the vegan version. 

Dr Olivia Pabois, a research fellow at Leeds and first author of the paper, said: “The test results provide a robust proof of concept that that our material is likely to be more effective under real-world conditions and could offer relief up to five times longer than the existing products. 

“The results of the benchmarking show favourable results in three key areas. Our microgel provides high moisturisation, it binds strongly with the surfaces of the mouth and is an effective lubricant, making it more comfortable for people to eat and talk.” 

Although testing of the new product has involved just laboratory analysis, the team believe the results will be replicated in human trials. 

Xerostomia is a common condition which affects around one in ten people and is prevalent among older people and people who have had cancer treatment or need to take a mix of medicines.