Tiny dexamethasone palmitate nanoparticles for intravitreal injection: Optimization and in vivo evaluation

Area of Science:

• Ophthalmology
• Nanotechnology
• Pharmacology

Background:

• Age-related macular degeneration (AMD) is a leading cause of vision loss.
• Intravitreal drug delivery faces challenges with nanoparticle stability and efficacy.
• Dexamethasone palmitate (DXP) shows potential for treating retinal diseases.

Purpose of the Study:

• To design and characterize dexamethasone palmitate (DXP) nanoparticles for intravitreal administration.
• To evaluate the influence of surfactants on nanoparticle properties.
• To assess the in vivo efficacy of DXP nanoparticles in restoring the blood-retinal barrier (BRB).

Main Methods:

• Nanoparticle formulation using three surfactants: PEG-40-stearate, Pluronic F68, and Pluronic F127.
• Characterization of nanoparticle size, stability, and morphology using TEM and XRPD.
• In vivo efficacy study in pigmented rabbits with induced BRB breakdown.

Main Results:

• Optimal formulation achieved using Pluronic F127, yielding stable, monodisperse, amorphous DXP nanoparticles (~35 nm).
• Intravitreal injection of DXP nanoparticles restored the BRB in rabbits one month post-injection.
• Efficacy was limited to two months, likely due to nanoparticle clearance.

Conclusions:

• DXP nanoparticles are a viable option for intravitreal delivery in AMD treatment.
• Pluronic F127 is an effective surfactant for stabilizing DXP nanoparticles.
• Further research is needed to enhance the duration of DXP nanoparticle efficacy.