Integration of Butterfly Pea (Clitoria ternatea L.) Flower Extract and ZnO into a Mouthwash: Physicochemical Characteristics and Antibacterial Activity

Butterfly pea (Clitoria ternatea L.) is a source of flavonoids with potential biological activity, while ZnO is known for its antibacterial properties, making their integration into a mouthwash formulation of particular interest. This study aimed to evaluate the physicochemical characteristics and antibacterial activity of a mouthwash integrating butterfly pea flower extract and ZnO. The extract was obtained by maceration using 70% ethanol, and its total flavonoid content was determined by UV-Vis spectrophotometry using the AlCl3-quercetin method. Mouthwash formulations were prepared with extract concentrations of 0.5% (F1), 1.0% (F2), and 1.5% (F3), while ZnO was maintained at 0.05%, with ZnO without extract used as a control. Evaluations included organoleptic properties, homogeneity, pH, viscosity, physical stability, and antibacterial activity against Staphylococcus aureus. The extract exhibited a mean absorbance of 0.3562 at 373.4 nm, corresponding to a total flavonoid content of 19.61 mg QE/g. F3 showed the best characteristics, with a pH of 6.08 ± 0.05, viscosity of 2.68 ± 0.07 mPa·s, good homogeneity, and no phase separation. F3 produced an inhibition zone of 13.67 ± 0.45 mm, higher than the ZnO control (8.21 ± 0.32 mm). These findings indicate that increasing the extract concentration to 1.5% at a fixed ZnO concentration produced a mouthwash with favorable physicochemical characteristics and the highest antibacterial activity among the tested formulations.