Estimation of anthelmintic compound 81/470 in cow's milk by high-performance liquid chromatography: method...

CDRI compound 81/470 is a new broad spectrum anthelmintic agent and is being developed for veterinary use. HPLC assay method for 81/470 in cow milk was developed and validated. The sample preparation consisted of protein precipitation, followed by extraction with ether. Separation was achieved on a C18 column using acetonitrile-buffer (pH 6, 50 mM) mobile phase and the compound was quantitated using fluorescence detector. The recovery of 81/470 was above 90% and was consistent over the calibration range of 10-1000 ng ml-1. Accuracy and precision were determined by analyzing replicate samples and were found to be within acceptable limits. Five freeze-thaw cycles of spiked milk and storage of processed dry residues at -30 degrees C for 7 days did not have any detrimental effect on the stability of 81/470.