Basic Research on the Association between Viscosity and Evaporation in Oral Moisturizers for Development of New Products

In general, oral moisturizers are used in oral health care for patients with xerostomia. Because oral moisturizers differ in their properties according to the products, it is important to select them according to the clinical condition of particular patients. To develop new oral moisturizers suitable for clinical conditions, we examined the association between density of viscosity and degree of evaporation in oral moisturizers. Carboxymethylcellulose (CMC) was used as a vicosity improver. Pure water and kinu-sui were used as solvents. We changed concentrations of CMC at intervals of 1% from 1% to 7% into solvents. We measured the weight of each preparation 1, 3, and 6 hours and 1, 2, and 5 days later. As for the results, there were relationships established between degree of evaporation and the length of time after mixture and also between degree of evaporation and the concentration of CMC.