抄録
Peplomycin (PEP), a new derivative of bleomycin, was prepared in a form of ethylcellulose microcapsules (PEP-m.c.) based on a modified phase separation method. PEP-m.c. had a mean particle size of 235μm with a rough surface and could be infused through a 18 G needle. Bioassay proved that the drug activity was not affected by the microencapsulation process employed. In vitro assay showed that PEP-m.c. has a slow release property, but the release rate in the early phase was considerably high, suggesting a need of modifications in the dosage form.
When PEP-m.c. were infused into the renal artery of the rabbits, a high drug activity was sustained in the kidney as compared with the nonencapsulated PEP infusion. Circulating blood level of PEP also decreased significantly in the PEP-m.c. group as compared with that in the control. Cytotoxic effects on the kidney tissues were markedly enhanced in the PEP-m.c. group as compared with those in other experimental groups treated with nonencapsulated PEP, placebo microcapsules or combination of the both.
The results indicate that selective arterial infusion of PEP-m.c. provides an intensive topical antitumor effects through a function of microinfarction and prolonged drug action.
