ABSTRACT
Background Econazole nitrate is not effective as an antifungal eyedrop because of its poor intraocular permeability,therefore changing the formulation of econazole nitrate to improve its intraocular permeability become a critical point in the treatment of intraocular fungal infection. Objective The present study was to observe the penetration of 0.5％ econazole nitrate nanoparticles in the corneas and aqueous humors following its topicaladministration. Methods Econazole nitrate nanoparticles were prepared by quasi-emulsion solvent diffusion.Characteristics and size of nanoparticles were examined with transmission electron microscope and laser scatteringmethod,respectively.Econazole nitrate nanoparticles drops (0.5％ )was topically administered in 27 New Zealandwhite rabbits bilaterally,and aqueous humor and corneas were obtained after the application of the eye drops for 5,15,30,45,60,90,120,180,240 minutes respectively to detect the concentration of econazole nitrate with highperformance liquid chromatography (HPLC). The pharmacokinetic parameters were calculated with 3 p97pharmacokinetic computer software.The use of the animals followed the Regulation for the Administration of AffairsConcerning Experimental Animals by State Science and Technology Commission. Results The diameter of thenanoparticles was 50 nm with the round shape and encapsulation efficiency was 96.0％.Econazole nitrate nanoparticlesat the concentration of 0.5％ could be rapidly separated with other elements by HPLC with a lowest quantitativeconcentration of 0.1 mg/L.The mean recovery rates of econazole nitrate nanoparticles were 98.09％ in cornea and 99.66％ in aqueous humor,respectively after topical administration.The peak levels of econazole nitrate nanoparticles in cornea and aqueous humor were achieved at 5 minutes after application ( cornea:40.620 μg/g± 7.756 μg/g;aqueous humor:0.504 mg/L±0.153 mg/L),and its half-life( t1/2 )in cornea and aqueous humor was 23.5 minutes and 18.6 minutes,respectively. Conclusions Econazole nitrate nanoparticles at 0.5％ concentration can remain a feasible bioavailability in ocular tissue and therapeutic level in cornea and aqueous humor.