A study of triclosan and its solubilizers as inhibitors of oral malodour

Background: It is known that the detergents or organic solvents used to solubilize lipid‐soluble triclosan can affect the biological activities exhibited by this molecule, such as its antibacterial, antiplaque, and anti‐inflammatory effects. Objective: To examine whether solubilizing agents influence the effect of triclosan against formation of volatile sulphur compounds (VSC), as these are known to be a major component of oral malodour. Material and methods: Part A: one ml of human whole saliva (n = 10) was incubated for 24 h at 37°C in a closed test tube with addition of 10 µl triclosan solubilized in alcohol. Part B: in a clinical experiment, VSC formation enhanced by mouth‐rinses with cysteine was followed by subjects (n = 9) rinsing with triclosan solubilized in different detergents and organic solvents. The amount and nature of VSC in the saliva headspace and in the mouth air of the test subjects were determined by gas chromatography. Results: Triclosan had a marked dose‐dependent effect against VSC in vitro when solubilized in alcohol, independent of the alcohol per se. In vivo, triclosan lost its anti‐VSC effect when solubilized in oil, in an uncharged detergent or in a chromophor, whereas it maintained its effect when solubilized in a combination of sodium lauryl sulphate, propylene glycol and water. Conclusion: The solubilizing agent influences the anti‐VSC effect of triclosan.