Spectrofluorimetric determination of benidipine in pharmaceutical preparation and spiked plasma samples using 7-fluoro-4-nitrobenzo-2-oxa-1,3-diazole

A new spectrofluorimetric technique was produced for the analysis of benidipine (BDP) in tablets and spiked plasma samples. The developed method was based on coupling between Benidipine, (a secondary amine group), and 7-fluoro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-F) forming fluorescent dervatived as a NBD-Benidipine. The reaction was occured by using pH 8.5 buffer solution to form fluorescent derivatives that are measured λem: 550 nm and λex: 465 nm. A variable parameters effecting on the derivatization process were studied. The calibration graph was linear in the range of 10–200 ng mL-1. LOD and LOQ values were a 0.445 ng mL-1 and 1.348 ng mL-1, respectivelly. The developed method was applied to BDP in commercially available film tablets. An average recovery was found as 99.80% without interference from the available excipients. Besides, the fluorimetric technique was also succesfully applied to spiked human plasma.