Spectrofluorometric quantification of Clozapine in pharmaceutical formulations and human plasma

Herein, we present a simple, precise, accurate, and ultra-sensitive spectrofluorimetric method for estimation of clozapine (CLZ) in tablets and human plasma was developed and then validated. A highly fluorescent brown-yellowish fluorophore was formed (λ_ex=469 nm, λ_emi=540 nm) as a nucleophilic substitution reaction occurred between CLZ and 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl) in alkaline mcllavine buffer (pH 9.0). Optimum values of experimental parameters were carefully determined and optimized. The calibration curve was rectilinear over the concentration range of 80-900 ng mL^-1 with a linear correlation coefficient (r=0.9984). The LOD and LOQ were determined to be 14 ng mL^-1 and 42 ng mL^-1, respectively. The proposed approach has been used successfully to quantification of Clozapine in its commercial formulations and human plasma.