Preparation, characterization and mucoadhesive evaluation of chitosan coated liposomes containing cyclosporine A

ABSTRACT

The aim of this study was to prepare and characterize chitosan coated liposomes containing cyclosporine A [CyA]. For this purpose, negatively charged liposomes containing CyA were prepared by solvent evaporation method. Liposomes were then added dropwise to chitosan solution [0.25% w/w] for coating. Morphology, mean size and encapsulation efficiency of chitosan coated liposomes were evaluated. To assess the mucoadhesive properties of this drug delivery system, percent of mucin adsorption onto the surface of coated liposomes was determined. The in vitro immunosuppressive effects of CyA encapsulated in the formulated liposomes were also determined on human T-cells by MTT [3- [4, 5- dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide] test. Liposomes were multilamellar vesicles [MLVs]. Mean diameter of chitosan coated liposomes was 2.76 micro m and zeta potential of them was positive [45.3 mV]. Encapsulation efficiency of coated liposomes was 86.11% +/- 2.36 and they were stable during two months. The average of IC50 or the half maximal inhibitory concentration for MLV liposomes was 3.08 2-10 M. According to the mucin adsorption results, this particulate system showed suitable mucoadhesive properties. From these results, it was concluded that the surface modification of liposomes by chitosan coating could increase the prospects of their usefulness as oral drug delivery systems for CyA