The effect of different dosages of degradable starch microspheres (Spherex) on the distribution of doxorubicin regionally administered to the rat.

To increase the effectiveness of intra-arterial treatment, embolizing agents are used. DSM (Spherex) is a starch microsphere suspension--mean diameter 45 mu--which can be used repeatedly to produce a transient vascular occlusion for about half an hour. It has been used experimentally and clinically in the treatment of liver cancer to increase the efficacy of drugs such as doxorubicin. In the present study the effect of DSM on the distribution of 14C-labelled doxorubicin was investigated in rats with liver tumours. A previously used pharmacological dose of 30 mg/kg DSM was compared to a lower dose of 12.5 mg/kg, especially regarding the intrahepatic distribution of co-injected drug at two and twelve hours after injection. The lower dose was to found to give a more effective tumour targeting as well as less regional toxicity. The results of the present study show that in experimental models lower doses of DSM should be beneficial.