Determination of PNU 153429, a new polysulphonated derivative of distamycin A, in rat plasma by reversed-phase ion-pair high-performance liquid chromatography with ultraviolet detection

Abstract

A rapid and selective ion-pair high-performance liquid chromatographic (HPLC) method for the determination of 2,2′-(carbonylbis(imino- N-methyl-4,2-pyrrolecarbonylimino( N-methyl-4,2-pyrrole)carbonylimino))-bis(1,5-naphtalenedisulphonic acid), tetrasodium salt (PNU 153429, I) in rat plasma has been developed. I is a new drug currently under investigation for the treatment of rheumatoid arthritis. Aliquots of 100 μl of plasma spiked with 10 μl of internal standard solution (PNU 145156E, I.S.) were added to 100 μl of acetonitrile and vortex mixed. After centrifugation, diluted aliquots of the supernatant were transferred to autosampler vials and analyzed by reversed-phase ion-pair liquid chromatography under isocratic conditions. The retention times of I.S. and I were ≈8 and 12 min, respectively. Quantitation was achieved by ultraviolet detection at 323 nm. The assay had a limit of quantitation of 0.1 μg ml −1 when 100 μl of plasma were analyzed. The linearity, precision and accuracy of the method were evaluated. No interference from blank rat, mouse, dog, monkey and human plasma was observed. The suitability of the method for in vivo samples was checked by analysis of plasma samples drawn from three cannulated male rats that had received a single 100 mg kg −1 i.v. dose of the test compound.