Role of Pluronic F127 micelles in enhancing ocular delivery of ciprofloxacin

In this study, Pluronic F127 micellar systems have been utilized to enhance ocular delivery of ciprofloxacin (CPX) antibiotic. Critical micelle concentration of the Pluronic F127 block copolymer had been determined in isotonic phosphate buffer at pH 7.4 and in simulated lacrimal fluid (SLF) at 25 and 34 °C. Micellar systems of Pluronic F127 have been accordingly used to improve CPX solubility in isotonic phosphate buffer solution at different pH. In vitro release rate of CPX from micellar systems was investigated in SLF. Ocular delivery of selected CPX micellar formulations has been investigated and compared with that of commercially available CPX eye drops (Ciprocin®) in rabbit's eye. Pharmacokinetic parameters such as Cmax, Tmax, elimination rate constant, t1/2, MRT and AUC0 − ∞ were determined. The results of this study showed that, Pluronic F127 micellar systems have been shown to significantly improve CPX solubility in isotonic phosphate buffer solution at different pH. The viscosity of these systems was low indicating the formation of aqueous eye drops. Also, in vitro release rate of CPX was significantly higher from Pluronic F127 system prepared at pH 4.5 and 6 than that at pH 7. The investigated micellar formulations showed a significant improvement in ocular delivery of CPX compared with that of commercial CPX eye drops.