Moxifloxacin in situ gelling microparticles-bioadhesive delivery system

Area of Science:

• Ophthalmology
• Materials Science
• Pharmacology

Background:

• Conventional eye drop formulations suffer from poor local bioavailability, limiting antibiotic efficacy in ocular treatments.
• Developing advanced drug delivery systems is crucial for sustained and effective local drug concentrations in the eye.

Purpose of the Study:

• To develop a controlled drug delivery system for moxifloxacin using poly(lactic-co-glycolic acid) (PLGA) microparticles encapsulated in a bioadhesive hydrogel.
• To achieve extended release of moxifloxacin over 10 days, maintaining concentrations above the minimum inhibitory concentration (MIC).

Main Methods:

• Fabrication of surfactant-free moxifloxacin-loaded PLGA microparticles (approx. 1 μm) using electrospraying with a methanol/dichloromethane solvent system.
• Encapsulation of microparticles within a chondroitin sulfate-based, two-component bioadhesive hydrogel.
• Evaluation of moxifloxacin release kinetics over 10 days and comparison with direct hydrogel loading.

Main Results:

• Electrospraying successfully produced moxifloxacin-loaded PLGA microparticles with controlled size.
• The PLGA microparticle system achieved sustained moxifloxacin release for 10 days, exceeding the MIC, unlike rapid release from direct hydrogel loading (within 24h).
• Increasing methanol content (10-30%) in the solvent system decreased the drug release rate, attributed to drug concentration gradients within microparticles.

Conclusions:

• The developed PLGA microparticle-hydrogel system offers a promising controlled delivery method for ocular moxifloxacin, significantly improving local bioavailability and treatment duration.
• The tunable release rate, influenced by solvent composition, allows for optimization of antibiotic delivery.
• This bioadhesive system has potential for integrated antibiotic prophylaxis and wound healing in ocular applications.