Purpose: The main purpose of this study was to increase the concentration and bioavailability of Ciprofloxacin (CPX) in the rabbit eye by liposomal formulation. Methods: CPX- loaded liposomes with and without Carbomer 934 (carbomer) were prepared by a thin-layer hydration method. Liposomal formulations after evaluation for characters such as particle size and entrapment efficiency were used in in-vivo experimental for installation into the rabbit's eyes. This experimental study consisted of 10 rabbits divided into two groups. Group 1 (liposomes without coating) and group 2 (carbomer coated liposomes) received one drop per h of liposomes consists of 0.3% CPX in the right eye and commercial CPX eye drop in the left eye until 6 h. Aqueous humor and vitreous samples were collected from all rabbits at the baseline, 1, 3 and 6 h and the drug concentration determined by high pressure liquid chromatography (HPLC). On the other hand, minimum inhibitor concentration (MIC) and minimum bactericidal concentration (MBC) of CPX-loaded in liposomes were determined. Results: liposomal formulations increased ocular bioavailability of CPX around four-folds compared with a commercial CPX eye drop. The increase in the ocular bioavailability may be effective and help to treat bacterial endophthalmitis as well as can be used in prophylaxis of post-operative endophthalmitis. Conclusion: The concentrations of CPX on the aqueous humor and vitreous after liposomes application were more than MIC of CPX against pseudomonas auroginosa and staphylococcus aurous but for commercial eye drop was less than MIC. Therefore liposomes modified the pharmacokinetics of CPX and improved pharmacodynamics property.
Keywords: Ocular bioavailability; carbomer; ciprofloxacin; endophthalmitis; liposome.