Mucoadhesive chitosan films as a potential ocular delivery system for ofloxacin: preliminary in vitro studies

Objective: The objective of the study is to evaluate the physical properties, in vitro release profile, and antibacterial efficiency of chitosan films prepared with ofloxacin.

Procedure: Mucoadhesive films were prepared by means of a casting and solvent evaporation technique performed in a 2 wt% acetic acid solution and distilled water. Physical properties were characterized by release and swelling studies, differential scanning calorimetry (DSC) analysis, and attenuated total reflectance Fourier transformed infrared spectroscopy (ATR-FTIR) analysis. The in vitro evaluation of the films was performed by inhibiting Staphylococcus aureus and Pseudomonas aeruginosa through activity studies.

Results: Circular ofloxacin-loaded chitosan-developed films with 0.3 mg of drug weighed 7 mg were 110 μm thick and 5 mm in diameter. The DSC curve of ofloxacin-loaded chitosan films suggests an amorphous dispersion of ofloxacin within these films. ATR-FTIR analysis showed that ofloxacin is indeed present in the matrix film. The drug was released in vitro over a 1-h period. No statistical difference could be observed between the ofloxacin-loaded chitosan films and sterile disk soaked for 1 min in 0.3% commercial ofloxacin ophthalmic solution for S. aureus and P. aeruginosa (P = 0.1686, P = 0.1172, respectively).The films presented a significantly larger mean bacterial inhibition zone of S. aureus than did the commercial ciprofloxacin control disk (P = 0.0002) and a significantly larger mean bacterial kill zone of P. aeruginosa than did the commercial enrofloxacin control disk (P < 0.0001).

Conclusions: Ofloxacin was successively incorporated onto chitosan films and was not inactivated during the process of manufacturing, thus preserving antibacterial proprieties.