Polymeric triamcinolone acetonide nanoparticles as a new alternative in the treatment of uveitis: in vitro and in vivo studies.

The purpose of this work was to improve the efficacy of triamcinolone acetonide (TA) in the treatment of endotoxin-induced uveitis (EIU) using a polymeric nanoparticulate drug delivery system. Poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles were prepared using a modified emulsification/solvent diffusion method. Processing factors affecting loading and size were also studied. After physicochemical studies including in vitro release, X-ray powder diffraction, differential scanning calorimetry, and scanning electron microscopy, in vivo studies were conducted using nanoparticles sized 195 nm with 3.16% drug loading. Inflammatory factors such as flare, cell, and fibrin were studied in rabbit's eye over 96 h period, using laser flare meter and slit lamp examination. Inflammatory mediators such as NO, PGE2, cell, and protein were measured quantitatively 36 h after intravitreal injection of endotoxin in aqueous humor, and the therapeutic effects were compared in different groups. Results indicated statistically significant differences between the effect of nanoparticles in the treatment of EIU compared to microparticles of TA and prednisolone acetate (PA). There were no significant differences between the effects of TA injection and TA nanoparticles. In conclusion, sustain release biodegradable TA nanoparticles are potential new topical treatment options which can provide better patient compliance.