Improving fluorescence emission of cyproheptadine by hindering its intramolecular photoinduced electron transfer (PET): Application to content uniformity testing and human plasma

The ability to determine antihistaminic drugs in biological matrices is critical for the medication adherence assessment. Among these antihistaminic medications, cyproheptadine (CPD); that is acting as a potent first-generation antihistaminic drug that has been extensively prescribed for allergic patients. Most of the established approaches for CPD detection are not appropriate for this purpose owing to their weak sensitivity, lack of rapidity, and complicated experimental procedures. Herein, we present a very fast, highly sensitive, and reproducible approach for the detection of CPD in its pure form, tablet formulation, and spiked human plasma. The photoluminescence approach depends on hindering the intramolecular photoinduced electron transfer (PET) effect of the lone pair of the N-atom present on the piperidine ring of CPD by making the surrounding medium acidic using 1.0 M acetic acid. Based on blocking PET, the target CPD drug has been sensitively detected from 5.0 to 500 ng mL^-1 with a very low detection and quantitation limit of 7.01 and 21.25 ng mL^-1, respectively. Moreover, the established approach was used for checking the tablet content uniformity testing for each tablet and spiked human plasma, and noteworthy, the matrices interference was insignificant.