DESIGN AND EVALUATION OF STEALTH LIPOSOMES ENCAPSULATING VINORELBINE TARTARATE

Vinorelbine tartarate (VRL) is an anticancer drug acting by inhibition of mitosis. It has been approved to treat metastatic breast cancer. Liposomes loaded with VRL were prepared by ethanol injection method using 1, 2-distearoyl-sn-glycero-3-phosphoglycerol,sodium salt (DSPG-Na) and cholesterol in different ratios. The drug incorporated was 5% of the lipid. The physicochemical characteristics, such as the particle size and zeta potential, of the optimized batches were in the range of 60±5nm (PDI-0.045±0.05) and -7.0±3.0mV, respectively. The drug content and entrapment efficiency were 80±5% and 73±3%, respectively. The optimized batch of liposome was further surface-modified using various concentrations of MPEG-DSPE2000. For the optimized pegylated (stealth) liposomes the particle size and zeta potential values were 74.5±5(PDI 0.243±0.05) and -3±5mV, whereas the drug content and entrapment efficiency were 85±5% and 75±3%, respectively. Light microscopic images revealed the exact morphology of liposomes. The in vitro release studies of liposome and stealth liposomes showed prolonged release upto 24 hours. The liposomes were stable at 40C and RT.