A radioimmunoassay method for the novel gastrointestinal prokinetic agent, renzapride, in plasma

Renzapride, BRL 24924 {4-amino-5-chloro-2- methoxy-N[4-(1-azabicyclo- [3,3,1] nonyl) benzamide]} is a novel compound that enhances gut motility without causing CNS dopamine block or prolactin release. It is being processed as a potential stimulant of upper gut motility and gastric emptying. Until now the only available method used to determine the concentrations of renzapride during clinical studies was a reversed phase h.p.l.c. assay (Kelly and Davies, 1988). Although the h.p.l.c. assay was used to determine renzapride in urine, the technique lacked the sensitivity required to quantify the low concentrations of the drug in plasma. The authors describe the development of a sensitive, specific, and simple radioimmunoassay method that can be used to determine renzapride concentrations in human plasma following therapeutic doses. (author)