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

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

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.

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).

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