Hyalugel-integrated liposomes as a novel ocular nanosized delivery system of fluconazole with promising prolonged effect

Fungal infections need long-term therapy with the proper antifungal agent. Despite effectiveness, Fluconazole (FLZ) ocular delivery is constrained by limited penetration, short residence time, in addition to the common barriers of the eye. Hyalugel-integrated liposomes were designed as novel ocular delivery systems integrating hyaluronic acid (HA) inside and surrounding vesicles by a simple preparation technique. The impact of combining HA hydrogel and liposomes was investigated in a series of different formulations. Full in-vitro optimization was performed regarding; HA and FLZ concentration, entrapment efficiency, particle size and stability to select the formula with the best characteristics. Structure elucidation of gel integration was done using polarizing and transmission electron microscopes before and after Triton-X100 addition. Corneal deposition and permeation were examined ex-vivo and in-vivo on male albino rabbits. Selected formulation (HYS7) showed gelintegrated structure, nanosize (218.50 +/- 4.50 nm) and % EE 42.81% +/- 1.66. Ex-vivo cumulative corneal permeation of FLZ after 6 h from HYS7, was 2.99 and 4.18 folds higher than conventional liposomes and FLZ suspension, respectively. In-vivo corneal permeation of HYS7 showed unprecedented sustained effect of FLZ reaching 24 h. In conclusion, novel hyalugel-integrated liposomes significantly enhanced corneal permeability compared to conventional liposomes and FLZ suspension. They would be promising alternates for eye drops; decreasing frequency of administration and increasing patients' compliance.