Determination of ethylenediamineplatinum(II) malonate in infusion fluids, human plasma and urine by high-performance liquid chromatography

A selective and convenient high-performance liquid chromatographic assay was developed for ethylenediamineplatinum(II) malonate (JM-40) in plasma ultrafiltrate and urine. A μPorasil silica column (30 cm) was used with acetonitrile-water (90:10, v/v) as the mobile phase and the elution of compounds was monitored by ultraviolet absorbance at 214 nm. A linear dynamic range of at least three decades (1-1000 μg/ml) was achieved. The detection limit in plasma ultrafiltrate was 0.35 μg/ml. The stability of JM-40 was determined in 0.9% sodium chloride, 5% glucose, plasma ultrafiltrate and urine. More stable drug solutions were obtained with 5% glucose than with 0.9% sodium chloride. JM-40 was also determined in plasma ultrafiltrate and urine samples of one patient receiving short-term infusions of the drug. In plasma ultrafiltrate unmetabolized JM-40 was detected during the first 5 h after administration and had a half-life of 21.3 ± 1.6 min. The parent drug was excreted in the urine in rapidly decreasing amounts. Eighteen per cent of the dose was recovered as unmetabolized drug during the first 6 h.