Biodistribution studies of BSA loaded gelatin microspheres after peroral application

Biodistribution studies of radiolabelled [131I]BSA loaded gelatin microspheres were carried out on BALB/c mice after peroral administration. To two groups, the radiolabelled [131I]BSA gelatin microspheres with different mean particle size, 1.196+/-1.961 and 7.028+/-1.231 microm were administered orally. To the control group, a solution of [131I]BSA was also orally administered. Biodistribution was followed periodically within 15 days as a percent of total radioactivity present in stomach, small intestine with Peyer's patches and mesentery, colon with Peyer's patches, appendix and mesentery, liver, spleen, blood, kidney, lungs and heart. The biodistribution data confirmed that uptake in mice into Peyer's patches and passage to the liver and spleen via the mesentery lymph supply and nodes, increased with decreasing particle size.