Development of a Specific Analytical Method forCis-Dichlorodiammineplatinum (II) in Plasma

Abstract

An analytical method has been developed to specifically monitor cis-dichlorodiammineplatinum (II) in plasma. The drug is separated from plasma protein and other macromolecular species by centrifugal ultrafiltration, which removes components with molecular weight greater than 50,000. The ultrafiltrate was then fractionated by HPLC. Mixtures were chromatographed on a strong anion exchange column and the eluent monitored spectrophotometrically (at concentrations of analyte exceeding 1μg/ml) or by atomic absorption spectrometry. Using the latter readout system, the detected limit for the analyte was 4 0 ng/ml of plasma at the 2s level and the detector output was linearly related to the drug concentration over the range 40–1000 ng/ml. The method appears to specifically respond to parent drug and is able to differentiate between it and other platinum species (metabolites or breakdown products) which may be present in the sample.