(PR87) Characterization and Antibacterial Activity of Sodium Hypochlorite and Chlorhexidine Nanoemulsions Mixture

Objectives: To prepare, analyze and evaluate a prepared mixture of sodium hypochlorite-chlorhexidine nanoemulsion, assess the presence of para-chloroaniline (PCA) and test its antibacterial efficacy.

Methods: Sodium hypochlorite-chlorhexidine nanoemulsions were prepared and mixed. Morphological analysis was performed using optical and transmission electron microscopy. Chromatography-ion trap mass spectrometer was used to characterize the presence of PCA. The Agar diffusion test was used to test its antibacterial activity on different microorganisms. For statistical analysis, a one-way ANOVA followed by a post hoc test at a significant level (p < 0.05) was done.

Results: The mixture design of the special cubic model to prepare NaOCl-CHX loaded-SNEDS with minimum globule size and maximum zeta potential was analyzed. The optimized formula was Oleic acid = 12.4%, Tween 80 = 47.7%, and PEG 200 = 39.9%. Immediate visual observation of the NaOCl.CHX-NE mixture showed spontaneous emulsification transparency without phase separation, color change, or drug precipitation. The analysis of NaOCl.CHX.NE mixture by liquid chromatography-ion trap mass spectrometer showed the absence of PCA with molecular mass 127.57. Between all tested microorganisms, NaOCl&CHX.NE mix showed a comparable antibacterial effect to other tested irrigants (p>0.05) while NaOCl-NE showed the lowest antibacterial activity (p < 0.05).

Conclusions: Mixing NaOCl and CHX nano-emulsions results in a transparent mix without PCA formation. Its antibacterial activity was almost similar to the antimicrobial effect of 5.25% NaOCl and 2% CHX without significant difference.