Phosphatidylcholine in the tear film of the eye: Enhanced topical delivery of fluorometholone to the eye

In this study, the ability of the phosphatidylcholine (PC) molecule, which is in the tear films in human eyes, to release the fluorometholone (FLU) drug from the sulfobutylether-beta-cyclodextrin (SBE-beta-CD) carrier, is investigated. The binding energy obtained from the density functional theory (DFT) calculations shows that the PC molecule affinity to bind with the SBE-beta-CD is higher than that of the FLU molecule. In addition, the results of molecular dynamic (MD) simulations revealed that PC could interact with the carrier through both coulombic and L-J interactions (Ecoul = --206 and EL-J = --190 kJ/mol), while FLU interaction with SBE-beta-CD is mainly via van der Waals interactions (Ecoul = --49 and EL-J = --125 kJ/mol). The obtained results show that in both studied systems, H-bond formation is the driving force in stabilizing these structures. The results confirmed that the Phosphatidylcholine could replace the fluorometholone in the carrier cavity and release the drug in the target site. Overall, our findings demonstrate that SBE-beta-CD&FLU complex can be a suitable alternative for treating inflammatory disorders of the eye over the conventional delivery systems.