OFLOXACIN ION PAIRING WITHIN SUBMICRON EMULSION: A POTENTIAL APPROACH FOR OCULAR DELIVERY

The aim of the work was to improve the entrapment of ofloxacin within the submicron emulsion by ion pairing with sodium deoxycholate to improve antimicrobial activity and precorneal retention. Partition coefficient of ofloxacin-sodium deoxycholate was found to be 3.788, compared to 0.113 for the drug alone. Formulation was characterized for globules size 0.143 ± 0.07 μm, viscosity 3.8 ± 0.2 cP and pH, 7.1 ± 0.3. The entrapment was 80 ± 1% for ofloxacin-sodium deoxycholate in submicron emulsion compared to 57 ± 2% for the drug alone. More than 90% drug remained after 90 days in optimized formulations and was found stable. SEM confirmed droplets size to be 200 nm and spherical. Drug released 53.16% after 24 h from optimized formulation. In vitro antimicrobial efficacy improved against S. aureus as compared to free drug. No toxicity of optimized formulation on HET-CAM test was observed. Designed formulation may hold some promise for severe ocular infections where frequent dosing is required.