Design and Evaluation of Voriconazole Loaded Solid Lipid Nanoparticles for Ophthalmic Application

Voriconazole is a second-generation antifungal agent with excellent broad spectrum of antifungal activity commercially available for oral and intravenous administration. Systemic administration of voriconazole is associated with side effects including visual and hepatic abnormalities. This study assessed the feasibility of using solid lipid nanoparticles for ocular delivery of voriconazole adopting stearic acid as lipidic material, tween 80 as a stabilizer, and Carbopol 934 as controlled release agent and for increasing the precorneal residence time in eye. The systems were prepared using two different methods, that is, ultrasonication method and microemulsion technique. The results indicated that the larger particle size of SLNs was found with microemulsion technique (308 ± 3.52 nm to 343 ± 3.51) compared to SLN prepared with ultrasonication method (234 ± 3.52 nm to 288 ± 4.58 nm). The polydispersity index values were less than 0.3 for all formulations and zeta potential of the prepared formulations by these two methods varied from -22.71 ± 0.63 mV to -28.86 ± 0.58 mV. Powder X-ray diffraction and differential scanning calorimetry indicated decrease in crystallinity of drug. The in vitro release study and the SLN formulations prepared with ultrasonication method demonstrated sustained release up to 12 hours. This study demonstrated that SLN prepared by ultrasonication method is more suitable than microemulsion technique without causing any significant effect on corneal hydration level.