Chitosan-Coated Liposomes: The Strategy to Reduce Intestinal Toxicity and Improve Bioavailability of Oral Vinorelbine

In recent years, the oral administration of vinorelbine has gradually replaced intravenous administration in the treatment of several types of tumors. Even though the risk of phlebitis is avoided with oral administration, oral vinorelbine is still not a highly patient-compliant route due to the severe gastrointestinal toxicity. Vinorelbine-loaded liposomes with high encapsulation efficiency and suitable particle size were prepared using the ammonium sulfate gradient method. Chitosan-coated liposomes showed the slowest in vitro release compared to uncoated liposomes and vinorelbine solution. No damage was observed in the intestinal epithelial cells of mice orally administered with coated vinorelbine liposomes due to the low presence of the free drug in the gastrointestinal tract and the LD 50 was increased from 129.83 to 182.25 mg/kg compared to oral vinorelbine solution. In addition, the positive surface potential of chitosan-coating endowed liposomes with mucosal adhesive function, delaying the time to reach the peak plasma concentration of vinorelbine from 1 to 4 h after administration. And bioavailability was increased to 2.1-fold compared to vinorelbine solution. In short, a new strategy to address the severe gastrointestinal side effects of oral vinorelbine has been developed.