Mouthwash Formulas for Xerostomia and Malodour

Abstract Xerostomia also known as dry mouth is often associated with bacterial malodour and oral-dental disorders. A successful treatment must provide oral hygiene and moisten the mouth. In this study, it was aimed to prepare mouthwash formulas using essential oils (1–6%), fixed oils and carboxymethyl cellulose that can meet both requirements. Citrus bergamia fruit peel oil, Cinnamomum zeylanicum leaf oil, Vitis vinifera L. and Corylus avellana L. seed oils was used as essential and fixed oils, which were analyzed by using GC-FD/MS. The organoleptic, pH, density, viscosity, antimicrobial activity, and cytotoxicity controls were conducted on the formulas. Stability studies were conducted in a stabilization cabinet at 25°C, 60%RH for 90 days, revealing that all formulations remained stable based on organoleptic assessments, pH, and density controls. Formulations containing 2% or more cinnamon oil exhibited antimicrobial activity against all investigated mouth pathogens (S. pyogenes, S. mutans, S. mitis, S. aureus, K. pneumonia, C. albicans) while formulations with 1–6% bergamot fruit peel oil displayed limited activity, proving ineffective against S. mitis. The most and the lowest cytotoxic formulations were respectively including 6% and 1% cinnamon oil (47,25% and 7,82%) while all the others were in acceptable range against gingival fibroblast cells. In conclusion, the formulation, comprising 2% cinnamon leaf oil, 2–4% hazelnut oil, and a 0.5% CMC solution, demonstrated successful physicochemical characterization with antimicrobial efficacy against all investigated mouth pathogens and exhibited acceptable safety in terms of cytotoxicity. This formulation holds promise for local treatment of xerostomia, malodor, and orodental infections.