Investigation on in situ Gel Based on Liposomal Vesicle

To develop a combination of lipid nanoparticle and polymer, liposomal vesicle was prepared by the film dispersion-high pressure homogeneous method, with lipid composition m (phosphatidyl choline) : m (cholesterol) = 3:1. Briefly, the organic phase containing m (lipid) :m (lutein) = 5:1 was dissolved in absolutely ether, the water phase was phosphate buffer containing 0.5% of Tween 80. The volume ratio of the former and the latter was 1.5:1. Liposomal vesicle in situ gel was developed by suspending F127 and F68 in liposomal vesicle. The effect of simulative tears and excipients on gelation temperature was determined by tube-reverse method and the sol-gel transition process during the heating was evaluated by rheological measure. Erosion of the gel and drug release from the gel in vitro were measured by membrane-free and high performamce liquid chromatography(HPLC), respectively. The liposomal vesicle in gel in situ kept solution state at room temperature and immediately formed gel in eye microenvironment. Gel erosion and gel drug relaease in vitro were kept a constant rate and both of them showed zero-order kinetic characteristics. In conclusion, a novel drug delivery system, liposomal vesicle in gel in situ was developed and characterized.