Abstract
Purpose:
Liposomes are microscopic structures consisting of concentric lipid bilayers enclosing an equal number of aqueous compartments. Liposome is one of the most effective tools for drug delivery systems. Liposome offers improved pharmacokinetic properties, controlled and sustained release of drugs. In this study, liposomes encapsulated human immunoglobulin were prepared and characterized.
Methods:
The liposomes were prepared using the improved cholate dialysis method. Dipalmitoylphosphatidylcholine, cholesterol, diacetylphosphate, ganglioside, dipalmitoylphosphatidylethanolamine, and sodium cholate were mixed. The mixtures were dissolved with chloroform/methanol solution. The solvent was evaporated using a rotating evaporator and the lipid film was obtained after drying under vacuum. The micelle suspension was obtained after sonicating. The human immunoglobulin was mixed with the micelle suspension, and then was ultrafiltrated. Liposomal nanoparticles were obtained. The size distribution of the prepared liposomal nanoparticles was determined by dynamic laser light scattering. The encapsulation efficiency was evaluated by micro bicinchoninic acid protein assay. The liposomes were incubated in isotonic saline at 37°C for 0, 3, 7, 14, 30, 45 and 60 days. The leakage of human immunoglobulin from liposomes under physiological conditions was evaluated after ultrafiltration by micro bicinchoninic acid protein assay.
Results:
The intensity-average diameter of the liposomal nanoparticles was approximately 100 nm. Encapsulation efficiency was approximately 16-21%. The size distribution of liposomes remained stable until 45 days. Liposome compositions used were unstable at 60 days. The efficiency of leakage at 0, 3, 7, 14, 30, 45 and 60 days was 0, 8, 9, 12, 18, 19 and 35 %, respectively. The leakage concentration of human immunoglobulin was gradually increased during the study period.
Conclusions:
The liposomes can lead to the slow and controlled release of drug in the vitreous. These results suggest that liposomes encapsulated with immunoglobulin for intravitreal administration may be feasible for antibody treatment of ocular diseases.
Keywords: 688 retina •
561 injection •
583 lipids