Antitumor effect of neocarzinostatin entrapped in liposomes

Antitumor effect against mouse Ehrlich ascites carcinoma was examined on Neocarzinostatin (NCS) entrapped in sonicated liposomes (neutral and negatively or positively charged forms) in comparison with free NCS. In the intraperitoneal inoculation-intraperitoneal medication system, NSC entrapped in negatively charged liposomes, which was most unstable in aqueous solution, showed statistically significant prolongation of survival days in mice compared to free NCS. In contrast, survival days of the animals given NCS entrapped in positively charged liposomes were shorter than those of the corresponding groups given free NCS. On the other hand in the intraperitoneal inoculation-intravenous medication system, survival days were not prolonged markedly by administration of free NCS, BUT WHEN NCS was entrapped in positively charged or neutral liposomes, prolongation of survival was apparent compared to the corresponding groups given free NCS. The most marked effect was seen when NCS was entrapped in positively charged liposomes, which show the best stability in aqueous solution.