Ion-paired moxifloxacin nanocrystal formulation improves treatment and prevention of ocular infection

Ocular infections may arise spontaneously or following penetrating globe injury or operation, such as corneal transplant or cataract extraction. Treatment and prophylaxis of bacterial infections using antibiotic eye drops requires a strict dosing regimen to avoid irreversible vision loss. At present, moxifloxacin eye drops are prescribed for use multiple times per day, leading to patient non-adherence, the emergence of bacterial resistance, and infection progression. The desire to avoid sub-lethal antibiotic dosing and visual impairment through inconsistent eye drop application motivates the development of a sustained release injectable formulation. Herein, we report the development of an ion-paired, nanocrystalline moxifloxacin formulation that provided increased intraocular antibiotic accumulation with a single subconjunctival injection compared to 3× daily eye drops. The sustained release functionality further led to improved or non-inferior prevention and treatment of Staphylococcus aureus-induced ocular infection in both rats and rabbits compared to gold standard intracameral moxifloxacin and moxifloxacin eye drops. By achieving therapeutically relevant moxifloxacin accumulation, this nanocrystalline moxifloxacin formulation may be a promising alternative to conventional therapies to achieve improved post-surgical infection prevention and bacterial keratitis treatment outcomes.