Local anesthetics effects of lidocaine-loaded chitosan nanoparticles in a rat model: An in vitro and in vivo study

Abstract

Due to low molecular weight, locally administered anesthetic drugs are drained or absorbed. In the current study, lidocaine was loaded into chitosan nanoparticles using ionotropic gelation method in order to develop a potential anesthetic formulation to improve the drug’s long term effects. in vitro experiments including scanning electron microscopy assay, cell viability assay, hemocompatibility assay, and release assay were used to characterize the delivery system in vitro. in vivo anesthetic function of the developed delivery system was investigated in a rat model. in vitro studies showed that the developed nanoparticles had a submicron size and a wide size distribution. Lidocaine-loaded and lidocaine-free nanoparticles had mean particle size around 301.92±67.92 nm and 313.73±73.97 nm, respectively. The prepared nanoparticles were not toxic against L929 cells and promoted their viability. in vivo studies showed that the anesthetic effects of lidocaine-loaded nanoparticles were longer-lasting than free lidocaine. This study suggests potential applicability of the developed delivery system for anesthetic applications in the clinic.