SENSITIVE METHOD FOR THE QUANTITATION OF DROLOXIFENE IN PLASMA AND SERUM BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY EMPLOYING FLUOROMETRIC DETECTION

A simple and highly sensitive reversed-phase fluorimetric HPLC method for the quantitation of droloxifene from rat, monkey, and human plasma as well as human serum is described. This assay employs solid-phase e xtraction and has a dynamic range of 25 to 10 000 pg/ml. Sample extrac tion (efficiencies >86%) was accomplished using a benzenesulfonic acid (SCX) column with water and methanol rinses. Droloxifene and internal standard were eluted with 1 ml of 3.5% (v/v) ammonium hydroxide (30%) in methanol. Samples were quantitated using post-column UV-photochemi cal cyclization coupled with fluorimetric detection with excitation an d emission wavelengths of 260 nm and 375 nm, respectively. Relative ea se of sample extraction and short run times allow for the analysis of approximately 100 samples per day.