3. Results and discussion
3.1. Particle size and zeta potential of chitosan nanoparticles
Size (including size distribution) and zeta potential are essential
characteristic parameters for nanosuspensions (Muller, Jacobs, &
Kayser, 2001). Size distribution profile of the chitosan nanoparticles
is shown in Fig. 1A. Chitosan nanoparticles had a mean
diameter of 108.6 nm with a narrow size distribution (Width:
11.3 nm; Polydispersity index: 1.000). As shown in Fig. 1B, the
chitosan nanoparticles had a zeta potential of þ49.50 mV (Fig. 1B).
For a physically stable nanosuspension solely stabilized by electrostatic
repulsion, a zeta potential of ±30 mV is required as a
minimum (Muller et al., 2001). All these data suggested that chitosan
nanoparticles prepared here were stable