Tween 85 Oil-in-Water Nanoemulsions with Incorporated Chlorhexidine Base

Abstract

The properties of oil-in-water nanoemulsions (NEs) that are stable for a long time (more than a month), which contain a non-micelle-forming surfactant, Tween 85 (Tw, polyoxyethylene(20) sorbitan trioleate), as a dispersed phase, with and without incorporated chlorhexidine (CH) base, have been studied by dynamic light scattering, UV spectroscopy, and potentiometry. It has been shown that the concentration of the dispersed phase in a range of 1–5 wt % has almost no effect on the differential curves of the particle-size distribution, electrokinetic potential of the particles, and dispersion-medium pH values. A linear dependence of the solubility (solubilization) of chlorhexidine base on Tw concentration has been found. The solubilization capacity of the NEs with respect to CH has been determined. The occurrence of intense mass transfer of CH with NE particles in an aqueous medium and the antimicrobial activity with respect to Staphylococcus aureus bacterium, which is resistant to some antibiotics, in particular, to methicillin, has been confirmed.