title: Time-dependent distribution and excretion of radiolabelled, semipermeable, stable magnetic microcapsules.
abstract: The time-dependent excretion and potential body retention of magnetic polyethyleneimine (PEI) microcapsules, methylated with [14C]methyl iodide have been investigated after intragastric administration to mice. Gastric emptying was rapid but about 10% of the administered dose was still present in the stomach after 6 h; the number of microcapsules within the small intestine remained approximately constant over 1-6 h. Excretion of microcapsules in the faeces was virtually complete (98.7% excretion within 72 h), with small amounts of radioactivity excreted via the urine or as [14C]CO2. There was no detectable adsorption or retention of microcapsules within the body as measured by either a whole-body autographic study or by direct quantitation of tissue radioactivity.
mesh_terms: D000818:Animals; D001345:Autoradiography; D002214:Capsules; D005243:Feces / Q000032:analysis; D008280:Magnetics; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D010539:Permeability; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D002214:Capsules