Sustainable and Green Fluorescence Method for the Determination of Cloperastine in Human Plasma: Greenness Assessment

A newly green method for the sensitive quantification of cloperastine, a cough suppressant, in spiked human plasma and its pharmaceutical formulation was designed for the first time. The established method depends on the enhancement of the weak fluorescence of cloperastine using 50 mM sulfuric acid to impair the photoinduced electron transfer produced from the nitrogen atom of piperidine moiety in cloperastine. This full protonation in an acid medium leads to an enhancement in the fluorescence of cloperastine, permitting its linear determination from 0.2 to 5.0 µg/mL with LOD and LOQ of 0.04 and 0.13 µg/mL, respectively. Moreover, the studied drug was estimated in its pharmaceutical market formulations as well as spiked human plasma. Furthermore, the greenness of the described method was evaluated.