Validated HPLC procedures for the analysis of MBY-28090 in human plasma and urine

The compound BMY-28090 (elsamicin A) is a new fermentation product with antitumor properties, which has the same aglycone as chartreusin but contains two novel sugars. To define the disposition of BMY-28090 during phase I trials, HPLC procedures were developed and validated for the quantitation of the drug in human plasma and urine. To 1.0 ml plasma were added 0.5 ml 0.2 M phosphate buffer (pH 8.0), 125 ng 1-naphthol (internal standard) in 25 microliters MeOH and 5 ml ethyl acetate. After mixing and centrifugation, 4 ml ethyl acetate layer was removed, evaporated to dryness, and the residue was dissolved in 250 microliters mobile phase and injected (200 microliters). To 1.0 ml urine were added 100 microliters MeOH and 1.0 ml 0.5 M succinate buffer (pH 4.0). After mixing (30 s) and sonication (1 min), the solution was filtered in an Amicon Centrifree micropartition unit and injected (30 microliters). An IBM C-8 column 5-microns and fluorescence detection (excitation at 254 mm, 418 nm emission filter) were used for both analyses. The mobile phases for plasma (2 ml/min) and urine (1.3 ml/min) were H2O/CH3CN (7:3 v/v) and H2O/CH3CN/MeOH (6:3:1 (v/v), respectively, with 1.5 ml 85% H3PO4 and 1.5 ml triethylamine/l. BMY-28090 eluted at 8-10 min and 1-naphthol, at 10-11 min. The standard curves were linear from 1 to 50 ng/ml plasma and from 10 to 1000 ng/ml urine. The within- and between-day precision was less than 3% for plasma and less than 5% for urine. Accuracies were within 6% of the nominal value and recoveries were 75% and 90% for plasma and urine, respectively.