Preparation and in vitro, in vivo evaluations of norfloxacin-loaded solid lipid nanopartices for oral delivery

This work aims to develop norfloxacin-solid lipid nanoparticles (NFX-SLN) as an oral delivery formulation. Hot homogenization and ultrasonic technique was employed to prepare NFX-SLN using stearic acid as lipid matrix and polyvinyl alcohol as surfactant. The physicochemical characteristics of SLN were investigated by optical microscope scanning electron microscopy and photon correlation spectroscopy. Antibacterial experiments of NFX-SLN were carried out by broth dilution technique. Pharmacokinetics was studied after oral administration in male Sprague-Dawley rats. The results showed that NFX-SLN was spherical and the SLN of the optimized formulation had diameters 301 +/- 16.64 nm, polydispersity index 0.15 +/- 0.04, zeta potential -30.8 +/- 0.69 mv, loading capacity 8.58 +/- 0.21% and encapsulation efficiency 92.35 +/- 2.24% with good stability at 4 degrees C. The NFX-SLN had sustained release effect and sustained bactericidal activity. Cytotoxicity studies in cell culture demonstrated that the nanoparticles were not toxic. NFX-SLN resulted in significantly higher plasma drug concentration than native NFX. The SLN increased the relative bioavailability of NFX by 12 folds, prolonged the plasma drug level above the average minimum inhibition concentration from 14 to 168 h. These studies demonstrate that NFX-SLN could be a promising oral formulation for enhanced bioavailability and pharmacological activities.