Competitive enzyme immunoassay for anti-ulcer agent, (-)-cis-2,3-dihydro-3-(4-methylpiperazinylmethyl)-2-phenyl-1,5- benzothiazepin-4(5H)-one hydrochloride (BTM-1086).

Abstract

An enzyme immunoassay for an anti-ulcer agent, (-)-cis-2, 3-dihydro-3-(4-methylpiperazinyl-metyl)2-phenyl-1, 5-benzothiazepin-4(5H)-one hydrochloride (BTM-1086) was established. It was based on the double antibody solid phase procedure. The antisera to BTM-1086 were raised in rabbits by immunization with BTM-1086-ovalbumin conjugate. The formation of sulfoxide and the lack of a methyl group in the thiazepine ring and the piperazine ring, respectively, of the BTM-1086 skeleton markedly decreased the binding affinity for the antibody.Horseradish peroxidase was conjugated with hydrazinomethyl-BTM-1086 by the use of glutaraldehyde. The first and second immuno reactions require 20 min and 2.5h, respectively. The assay allows determination of 2.5-100pg of BTM-1086. This enzyme immunoassay has high sensitivity, and the results are reproducible. The time course of serum BTM-1086 level was also examined after a single intravenous administration in rats.