MAGNETIC GRANULES - A NOVEL SYSTEM FOR SPECIFIC DRUG DELIVERY TO ESOPHAGEAL MUCOSA IN ORAL-ADMINISTRATION

Presuming an application to targeting therapy for esophageal cancer, magnetic granules containing ultrafine ferrite (γ-Fe2O3), brilliant blue FCF, and bioadhesive polymers (10:1:9 w/w) were prepared, and their properties as a drug carrier were examined in vitro and in vivo. When 5 mg of granules containing a mixture of hydroxypropyl cellulose (HPC) and Carbopol 934® (6:4 w/w) was flushed into an agar-gel tube with 20 ml of 0.65% HPC solution, about 90% of the granules were held in the region of the applied magnetic field (about 1700 G). Holding of the magnetic granules was influenced by the viscosity of the solution, magnitude of the magnetic field and the ferrite content of granules. The granules were administered to rabbits with about 2 ml of 0.65% HPC solution via catheter without anesthesia. Approximately the entire amount of granules was held in the region at 2 h after administration with magnetic guidance for the initial 2 min. The results indicate that the new targeting system presented might be useful for local chemotherapy of esophageal cancer and also for other diseases of the alimentary canal. © 1990.