Triamcinolone (TA) is a hormone corticosteroid drug used to treat edema, inflammation, and angiogenic eye diseases. It can be administered by intravitreal injection at an early stage. The intraocular instillation method can improve the bioavailability of TA by loading the drug on to a nanostructured lipid carrier (NLC). The nanoparticles (20 to 200 nm) used in this experiment were previously prepared by high-pressure homogenization using a factorial optimization design method. The NLC produced contained a distinct peak with a negative charge. The nanoparticles were loaded with drugs (TA-NLC) and fluorescent Nile Red lipids. Using the treated nanoparticles, NR-NLC was dripped into the eyes of mice in an in vivo test, demonstrating the ability to deliver lipophilic active substances to the posterior ocular segment. The short- and long-term stability of TA-NLC was also evaluated using a Turbiscan® high-performance stability analysis. Results showed that backscattering in the 6-month stability test was less than 1.5%. When stored at room temperature, the possibility of the nanoparticles condensing into flocs during the storage period is very small.