Versatile applications of a spectrofluorimetric approach based on photo-induced electron transfer blocking of Lurasidone

Photo-induced electron transfer (PET) is one of the most common intermolecular causes that could be responsible for the fluorescence quenching of several fluorophores. Lurasidone is one of these compounds which intrinsic fluorescence could be turned OFF" in alkaline medium because of the PET effect of the amino group of the piperazine ring. Upon protonation of the piperazine nitrogen atom, its electron lone pair was removed, and hence the fluorescence could be recovered, and the fluorescence is turn ON. Accordingly, a new, simple, environmentally friendly, and selective approach with high sensitivity was developed for quantitation of Lurasidone hydrochloride. The technique relies on measuring the strong native fluorescence of the drug in aqueous solution, which was excited at 316 nm and emitted at 398 nm. Lower detection and quantification limits of 12.9 and 39.0 ng mL-1 were achieved. The fluorescence concentration plot was rectilinear in the range of 30-1600 ng mL-1 with a correlation coefficient of 0.9998. The drug concentrations in commercial tablets and spiked plasma were estimated using the indicated method. The suggested approach was also used to assess how closely commercial tablets complied with USP requirements for content uniformity.