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

Abstract
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 0.2M phosphate buffer (pH 8.0), 125 ng 1-naphthol (internal standard) in 25 μl 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 μl mobile phase and injected (200 μl). To 1.0 ml urine were added 100 μl MeOH and 1.0 ml 0.5M 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 μl). An IBM C-8 column 5-μm 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/1. 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 <3% for plasma and <5% for urine. Accuracies were within 6% of the nominal value and recoveries were 75% and 90% for plasma and urine, respectively. At 37°C, BMY-28090 was stable in plasma for at least 8 h but had a half-life of 36 h in urine. The drug was stable in plasma and urine for 30 days at −20°C.