HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF GRANISETRON IN HUMAN PLASMA

This paper describes a high-performance liquid chromatographic method (HPLC) with fluorometric detection for the analysis of granisetron in plasma. The detection is performed at 305 nm for excitation and 365 nm for emission. The method involves sample clean-up by liquid-liquid ex traction. N-(1-Naphthyl) ethylenediamine dihydrochloride is used as in ternal standard. Toluene and phosphate buffer were added to 0.5 ml of plasma added to the internal standard. After extraction, the organic l ayer was separated and then evaporated to dryness. The residue was rec onstituted in eluent mixture. An aliquot was injected onto the HPLC co lumn, Spherisorb CN, equilibrated with an eluent mixture constituted b y acetonitrile-phosphate buffer (pH 4.5) (15:85). The proposed techniq ue is reproducible, selective, reliable, and sensitive. Linear detecto r responses were observed for the calibration curve standards in the r ange of 0.50 to 100 ng/ml. Extraction recovery from plasma proved to b e more than 90%. Precision expressed as C.V. was in the range 2 to 8%. As low as 0.3 ng of granisetron per ml of plasma can be measured with good accuracy. The method has been validated, and stability tests und er various conditions have been performed. Its sensitivity is adequate for pharmacokinetic studies.