Quantification of Suramin by Reverse-Phase Ion-Pairing High-Performance Liquid Chromatography

Abstract

A specific and sensitive method has been developed for the separation and quantification of suramin and trypan blue (internal standard) in human plasma. Plasma samples were extracted by centrifugation after the addition of ion-pairing reagent (tetra-butylammonium phosphate, TRAP) and methanol. Extracts were injected directly onto a reverse-phase ion-pairing HPLC system with 5 mM TBAP in the mobile phase. There was nearly 100% extraction efficiency after 3 cumulative extracts of each sample. The limit of quantitation was 0.5 μg/ml at a detection wavelength of 313 nm. Analysis of 3 post-therapy samples from a patient with AIDS was used to determine a plasma half-life for suramin of at least 3 weeks.