Development and optimisation of esculin-loaded chitosan microspheres for intravitreal injection

Area of Science:

• Ophthalmology
• Materials Science
• Pharmacology

Background:

• Macular degeneration is a leading cause of vision loss.
• Current treatments for macular degeneration have limitations.
• Effective drug delivery systems are needed to improve therapeutic outcomes.

Purpose of the Study:

• To prepare esculin-loaded chitosan microspheres for intravitreal injection.
• To evaluate the feasibility of this system for treating macular degeneration.
• To characterize the drug loading, encapsulation efficiency, particle size, stability, in vitro release, and pharmacokinetics.

Main Methods:

• Chitosan microspheres loaded with esculin were fabricated using an emulsification crosslinking technique.
• Microsphere characteristics including drug loading, encapsulation efficiency, and particle size were determined.
• In vitro drug release, thermal stability, and pharmacokinetic parameters after intravitreal administration were analyzed.

Main Results:

• Optimized microspheres exhibited high drug loading (8.03%) and encapsulation efficiency (93.03%) with a mean particle diameter of 4.81 μm.
• Microspheres demonstrated good thermal stability, maintaining particle size over 30 days.
• In vitro studies showed 80% cumulative drug release over 72 hours, with significantly enhanced pharmacokinetic parameters (t1/2 = 879.88 min, AUC = 150.18 × 10^3 mg·min/mL) in the vitreous humor.

Conclusions:

• Esculin-loaded chitosan microspheres are a viable formulation for intravitreal injection.
• The developed system provides sustained drug release and improved pharmacokinetic profiles.
• This drug delivery system holds promise for the effective treatment of macular degeneration.