LISTERINE® was originally formulated using ethanol (alcohol), which allows the essential oils to mix with the water base and acts as a preservative. Today, ethanol is a component of the LISTERINE® base range and the LISTERINE®Total Care mouth rinses. In both the base range and the Total Care range, LISTERINE® has ethanol-free variants (LISTERINE® Zero and LISTERINE® Total Care Zero respectively).
Ethanol has a number of roles in LISTERINE® mouth rinse:
- Ethanol in LISTERINE® helps dissolve the essential oils in water in the formulation to create a clear homogenous mixture
- It helps to carry the essential oils quickly into the plaque-biofilm matrix
- It acts as a preservative, helping to stabilise the product and protect it against microbial contamination
- The level of ethanol in LISTERINE® represents the optimum concentration to ensure the most efficient delivery of the anti-plaque ingredients
- Alcohol-free mouth rinses, such as LISTERINE® Total Care Zero, contain a patented mixture of non-ethanolic solubilising agents that perform a similar role to alcohol
It has been suggested that the ethanol in mouth rinses may cause or exacerbate xerostomia (mouth dryness). It has also been controversially linked with an excess incidence of oral cancer.
Xerostomia is the subjective experience of mouth dryness. This is a common condition, with a prevalence of 20% in the general population, with a higher prevalence of up to 50% in the elderly.1