To improve
therapy for peritoneal dissemination, and the distributions of
doxorubicin (DOX) in the abdominal cavity, solid
tumor and normal tissues after intraperitoneal administration of DOX-encapsulating
liposomes was examined. In small negatively charged
liposomes,
lipid composition did not affect the clearance or stability of
liposomes in the abdominal cavity. Whereas, for the treatment of solid
tumor and the reduction of side effects, L-alpha-
distearoylphosphatidylcholine-containing
liposomes were most effective. On the other hand, large
liposomes (DS(L)-Lip) were most abundant in the abdominal cavity. As the DOX levels in the heart, liver and solid
tumor after DS(L)-Lip injection were lower than the corresponding values for the small
liposome group, we considered that DS(L)-Lip were disrupted in the abdominal cavity and DOX was released from the
liposomes. DS(L)-Lip remain in the abdominal cavity for a long time inducing cytotoxicity. The survival of Ehrlich
ascites carcinoma-bearing mice was considered to be prolonged by DS(L)-Lip.
Liposomes, both small and large in size appear to be effective against solid
tumors except in the abdominal cavity, and against peritoneal dissemination in the abdominal cavity, respectively.