Mechanism of transfer of bleomycin into lymphatics by bifunctional delivery system via lumen of small intestine.

Abstract

The mechanism of lymphatic transfer of bleomycin [an anticancer drug] from the lumen of the small intestine of rats following the administration of a bifunctional delivery system was investigated. This system is a combination of macromolecular bleomycin.cntdot.dextran sulfate complex as a lymphotropic carrier and lipid-surfactant mixed micelles as an absorption promoter. After administration of this bifunctional delivery system into the lumen of the small intestine, 56% of the complex was left intact in the lumen after 2 h, but 85, 95 and 97% of the absorbed bleomycin were detected as the free drug in the tissue of the small intestine, the lymph and the blood, respectively. The absorption percentage of bleomycin from the lumen of the small intestine at 3 h after the administration of the bifunctional delivery system was significantly different from that of dextran sulfate, and the total lymphatic transfer of dextran sulfate was greater than that of bleomycin. The extent of the selective lymphatic transfer of bleomycin was apparently smaller than that of dextran sulfate because of the dissociation of the bleomycin.cntdot.dextran sulfate complex in the lumen and the tissue of the small intestine.