RADIOIMMUNOASSAY FOR THE MEASUREMENT OF S9788 IN SERUM AND MICRODIALYSIS SAMPLES

S9788, yl]-N,N'-di-2-propenyl-1,3,5-triazine-2,4-diamine, is a novel c ompound designed to reverse tumour multidrug resistance associated wit h cancer chemotherapy. A specific and sensitive radioimmunoassay has b een developed for the analysis of S9788 in serum samples and adapted f or samples obtained by microdialysis. The limit of quantitation is 0.2 ng ml(-1) in perfusion medium and there is no cross reactivity of the antibody with known metabolites of the parent compound or with certai n cytotoxic compounds likely to be coadministered with S9788. Maximum probe recovery during microdialysis was 66% at a flow of 1 mu l min(-1 ) using Ringer/BSA (70 mg ml(-1)) as the perfusion medium. The assay h as sufficient sensitivity, precision, accuracy and specificity for the analysis of rat and human serum and microdialysis perfusate samples. The assay has been successfully applied to the determination of S9788 in rat plasma (total concentration) and the microdialysate of the same samples. (C) 1997 Elsevier Science B.V.