Development and Characterization of Moxifloxacin Hydrochloride Cubogel for Enhanced Ocular Drug Delivery

Purpose The study aimed to formulate and evaluate an ocular effective prolonged release cubogel formulation of Moxifloxacin Hydrochloride (MX-Cubogel) to treat conjunctivitis. Materials and Methods Initially, a Moxifloxacin-loaded cubosome (MX-Cubosome) was prepared using a top-down technique using glyceryl monooleate and poloxamer 407 in different concentrations. The optimized MX-Cubosome was selected based on the physicochemical characteristics and was used to prepare MX-Cubogel by dispersing the cubosome into an in situ gelling system using the cold method. Physicochemical characterization, drug-polymer interaction studies, and histopathological studies were performed. Results Twelve MX-Cubosomal dispersions were prepared. The cubosomes were consistent, aggregate-free, and milky white. Particle sizes ranged from 306.5 to 714.2 nm, with a uniform size distribution. Zeta potentials were between -27.9 and -39.8 mv and encapsulation efficiencies ranged from 69% to 85%. Electron microscopy confirmed the nano-sized structure of the cubosomes. The MX-Cubogels were clear, with no visible impurities. Four formulations (MB11, MB12, MB15 and MB16) gelled immediately and remained stable over time. The gelation temperatures of the majority of formulations were between 28°C and 43°C. MX-Cubogels had a drug content of 92.5% to 97.7%. Four formulations (MB4, MB7, MB10 and MB13) released more than 95% of the drug over 12 hr. The antibacterial activity of the MX-Cubogels was demonstrated by an inhibition zone of 32 mm, which was greater than the standard (27 mm). Histological examination of goat corneas treated with selected formulations (MB4, MB7, MB10 and MB13) showed normal structures, with no changes in the epidermal layer after cubosomal formulation penetration. Conclusion The study demonstrates that MX-Cubosome dispersions can be successfully formulated as in situ gels (MX-Cubogel) with sustained release and antibacterial activity. The gels are also non-irritating to the cornea. MX-Cubogel might be a good alternative to conventional eye drops.