Inhibition of Endotoxin-Induced Uveitis by Methylprednisolone Acetate Nanosuspension in rabbits

Purpose: In the current investigation, nanoformulations of methylprednisolone acetate(MPA) were formulated using Eudragit®RS100 to study their impacts on inhibition of inflammatory symptoms in rabbits with endotoxin-induced uveitis (EIU).Methods: A modified quasi-emulsion solvent diffusion (QESD) technique was used for preparation of nanoparticles. The drug release profiles and physicochemical characteristics of the nanoformulations were studied by means of the X-ray crystallography, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR). Particle size analysis yielded mean diameter of approximately 380, 460 and 580 (nm) for MPA-Eudragit®RS100 nanoparticles at the ratios of 1:2.5, 1:5 and 1:10, respectively. Major clinical symptoms of EIU (morphological changes, leukocytes numbers and protein levels within the aqueous humor) were examined. Results: Upon the physicochemical characterizations, no crystal changes or chemical interactions were observed for MPA-Eudragit®RS100 nanoparticles. The 1:2.5 ratio of drug-polymer resulted in the most controlled release of MPA. The in vivo examinations revealed that the endotoxin induced inflammation can be inhibited by the MPA-Eudragit® RS100 nanosuspension more significantly than the microsuspension of MPA itself in the rabbits with EIU. Conclusion: Based on our findings, we suggest that the MPA-Eudragit®RS100 nanosuspension may favor the localized controlled ocular delivery of MPA for prevention of inflammatory symptoms in ocular diseases