THE UPTAKE OF FENBENDAZOLE BY CATTLE AND BUFFALO FOLLOWING LONG-TERM LOW-LEVEL ADMINISTRATION IN UREA-MOLASSES BLOCKS - FURTHER-STUDIES ON BLOCK FORMULATIONS

Fenbendazole (Hoechst India Ltd.) was incorporated at 0.5 g/kg into ur ea molasses blocks made by two different processes. The proportion of the drug remaining in the blocks and the plasma concentrations of the parent compound and its metabolites were measured. Recovery of the dru g in blocks made by the cold and the modified hot processes was 90% an d 96%, respectively. The plasma metabolite profile revealed a plateau between days 4 and 6 of feeding in cattle and buffalo. However, the pl asma concentrations of fenbendazole and its metabolites were low in bu ffalo compared to cattle.