2.1. Preparation of Blank and Naringenin-Loaded Chitosan Nanoparticles (NAR NPs)

NAR NPs were produced using ionic gelation method as described in Tzeyung et al., (1). Chitosan was dissolved in aqueous acetic acid (1% v/v) solution and drug NAR in different concentration was dispersed in chitosan solution under continuous stirring to obtain final mixture of NAR with chitosan solution. Next, TPP solution as a crosslinker was added to the chitosan solution drop wise with constant stirring (600 rpm) at room temperature for 30 min. NPs were prepared after mixing of optimal concentration of polycation solution of chitosan and polyanion solution of TPP. The resulting NAR NPs formed were pelleted by centrifugation for about 40 min at 20,000 rpm. The prepared pellet was freeze-dried for further characterization and the supernatant solution was used to measure the entrapment efficiency. The drug free chitosan nanoparticles (blank NPs) were obtained using the same procedure.