Abstract
Purpose:
We introduce the fluorometholone (FM) nanoparticle eye drops (FMNP; 0.1% w/w) which we developed. The preparation method and the physicochemical properties of the FMNP are reported. To demonstrate the superiority of FMNP, the dispersion stability of eye drops as well as the ocular penetration in rabbit are reported comparing with a conventional FM microparticle suspension (FMMS).
Methods:
The FMNP (0.1% w/w) was prepared by the freeze-dry-bottom-up technique which we developed (patent application). The size and morphology of nanoparticles were investigated using scanning electron microscopy (SEM) observation. The particle dispersion and z-potential of nanoparticle eye drops were evaluated using Zeta-potential & Particle size Analyzer. The FMNP (50 μl) was administrated into one eye of each rabbit. After the given interval of 30 min and 1 hour, the aqueous humor (200 μl) was collected using syringe (30G needle) from the rabbit after anesthesia treatment. The concentration of FM in aqueous humor was measured using high pressure liquid chromatography (HPLC). As comparison, FMMS prepared by ultrasonic treatment was under the experiment as the same manner as that of the FMNP. Rabbits were treated in accordance with the ARVO Statement on the Use of Animals in Ophthalmic and Visual Research.
Results:
The average particle size of FM nanoparticles was around 150 nm in SEM observation. The z-potential of FM nanoparticle water dispersion was around -10 mV, which made the FMNP stable because the interparticle repulsion caused in negative charge prevented the aggregation between particles. In fact, the FMNP took stable dispersion at least for 2 weeks without particle settling down. The concentration of FM in aqueous humor showed 200 ng/ml and 20 ng/ml in 30min after eye drops administration for FMNP and FMMS, respectively. In 60 min after eye drops administration, the concentration of FM in aqueous humor showed 214 ng/ml and 105 ng/ml for FMNP and FMMS, respectively. Totally, the FMNP achieved about 3-fold high ocular penetration compared to FMMS.
Conclusions:
FM nanoparticle eye drops (FMNP) we developed has quite superior peculiarity in stable dispersion and ocular penetration compared to conventional FM microparticle suspension (FMMS). We believe that the high quality FMNP will improve the efficacy of eye drops in near future as forwarding the further investigation.
Keywords: 607 nanotechnology •
608 nanomedicine