Development and Consumer Assessment of a Dry Mouth Rinse

Introduction: Dry mouth is a condition that causes overall dryness in the oral cavity and throat, difficulty speaking, eating and swallowing, burning mouth, etc.  Most sufferers tend to sip water or other beverages to provide a feeling of moisture replenishment.  This effect is short lived as these liquids do not provide the muco-adhesive coating properties of natural saliva. 

Objectives: To describe the rheological characteristics and consumer assessment of a mouth rinse formulated to relieve the symptoms of dry mouth.

Methods:

(1) The rheological profile of Colgate Dry Mouth Relief (CDM), Biotene Mouthrinse (BM), Oasis Mouthrinse (OM) and natural saliva were characterized using a stress control rheometer (Model: AR2000ex, TA Instruments) with a cone and plate geometry. Strain sweeps and flow curves were generated for each product to characterize viscoelastic properties and shear thinning behavior respectively.  Flow rate index, n, and consistency index, k, were derived by application of a power law model. 

(2) Blinded samples of CDM and BM were evaluated by 283 dry mouth panelists for 5 days.  Telephone interviews were conducted to obtain panelist feedback.

Results:

The flow rate index values were 0.5, 1.0, 0.9 and 0.41 for CDM, BM, OA and natural saliva, respectively.  The consistency index values were 119.7, 25.65, 6.76 and 63.77 (cps) for CDM, BM, OA and natural saliva, respectively.

CDM was preferred (40%) over BM (30%) for relieving dry mouth symptoms (p<0.05).

Conclusions: The CDM formula has a rheological profile more similar to natural saliva than commercially available mouthrinses.  Qualitative and quantitative evaluation of the CDM formula demonstrates its ability to relieve dry mouth symptoms for an extended length of time through actual product usage.  The viscoelastic properties of CDM being more similar to natural saliva as compared to other marketed rinses may be responsible for the perceived effectiveness.