Ethiodized oil emulsions in hepatic microcirculation: In vivo microscopy in animal models

Rationale and Objectives. The authors' purpose was to define the stability and drug-carrying and drug-releasing capacity of ethiodized oil emulsions in the hepatic circulation. Methods. Emulsions prepared in various ratios of a nonionic contrast material containing doxorubicin to ethiodized oil were injected into the hepatic arteries of normal and tumor-bearing livers in rats or mice. In vivo microscopy was used to observe the dynamic distribution of the emulsions in the hepatic circulation. Results. A solution of less water mixed with more oil formed water-in-oil (w/o) phase emulsions, whereas less oil with more water formed oil-in-water (o/w) emulsions. The oil in the emulsions carried the water in the blood circulation. The w/o emulsions exhibited significantly higher carriage capacity and longer release time for the drug solution than did the o/w emulsions (P < .01). Conclusion. The delivery capacity of w/o emulsions is superior to that of o/w emulsions. Further studies about preparation methods and delivery capability of emulsions in the liver are warranted.