Pk. Sanyal et Dk. Singh, THE UPTAKE OF FENBENDAZOLE BY CATTLE AND BUFFALO FOLLOWING LONG-TERM LOW-LEVEL ADMINISTRATION IN UREA MOLASSES BLOCKS, Veterinary research communications, 17(2), 1993, pp. 137-142
Fenbendazole (Panacur bolus, Hoechst India Ltd) was incorporated at a
rate of 0.5 g/kg into urea-molasses blocks made by two different proce
sses. The concentration of the drug in blocks and its bioavailability
were measured using plasma oxfendazole as marker. The recovery of the
drug in blocks made by a warm process was 68% and the plasma oxfendazo
le concentration remained fairly stable at 0.2 and 0.12 mug/ml from da
y 6 of feeding in cattle and buffalo, respectively. The drug seemed to
be inactivated in blocks made by a hot process, with reduced bioavail
ability. A low and sustained plasma concentration of the active metabo
lite of the drug could be maintained by self-medication using urea-mol
asses blocks as fenbendazole carrier.