Competitive Enzyme Immunoassay for Anti-ulcer Agent, ( — )-cis-2,3-Dihydro-3-(4-methylpiperazinylmethyl)-2-phenyl-l,5- benzothiazepin-4(5H)-one Hydrochloride (BTM-1086)

Abstract

An enzyme immunoassay for an anti-ulcer agent, ( — )-as-2,3-dihydro-3-(4-methylpiperazinyl-methyl)-2-phenyl-l,5-benzothiazepin-4(5//)-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 2.5 h, respectively. The assay allows determination of 2.5—l00 pg 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. © 1986, The Pharmaceutical Society of Japan. All rights reserved.