Besifloxacin-Loaded Nanostructured Lipid Carrier for Ocular Delivery: Formulation Optimization, In Vitro...

Area of Science:

• Ophthalmology
• Nanotechnology
• Pharmaceutics

Background:

• Bacterial eye infections like conjunctivitis are common, with topical treatments facing bioavailability challenges.
• Current besifloxacin (BFX) eye drops are suspensions with poor solubility, requiring frequent application and risking antimicrobial resistance.
• Nanostructured lipid carriers (NLCs) offer a potential solution for improved ocular drug delivery.

Purpose of the Study:

• To develop and optimize besifloxacin-loaded nanostructured lipid carriers (BFX-NLCs) for enhanced topical ocular delivery.
• To evaluate the physicochemical properties, in vitro release kinetics, antimicrobial activity, and stability of BFX-NLCs.
• To assess the safety and suitability of BFX-NLCs for ophthalmic applications.

Main Methods:

• BFX-NLCs were prepared using high-pressure homogenization and optimized via response surface methodology.
• Particle size, polydispersity index, and entrapment efficiency were characterized.
• In vitro drug release studies in simulated tear fluid were conducted, and release kinetics were analyzed.
• Antimicrobial activity was tested against Staphylococcus aureus and Pseudomonas aeruginosa.
• Cytotoxicity was evaluated using the Galleria mellonella larvae model, and physical stability was assessed over nine months.

Main Results:

• Optimized BFX-NLCs achieved a particle size of ~100 nm, PDI <0.25, and ~75% entrapment efficiency.
• Sustained BFX release of ~65% was observed over 24 hours, following anomalous diffusion kinetics (Korsmeyer-Peppas model, n=0.86).
• BFX-NLCs retained antimicrobial efficacy comparable to free BFX and demonstrated non-toxicity in vivo.
• The formulation exhibited suitable viscosity, osmolality, and long-term physical stability.

Conclusions:

• Besifloxacin-loaded nanostructured lipid carriers (BFX-NLCs) represent a viable lipid-based platform for topical ocular drug delivery.
• BFX-NLCs demonstrate potential for improved therapeutic efficacy and reduced dosing frequency in treating bacterial eye infections.
• This formulation offers enhanced ocular bioavailability and stability compared to conventional besifloxacin eye drops.