A fluorescence chemo sensor approach for determination of finerenone in pharmaceutical formulation and human plasma: Method development and validation.

Finerenone, a non-steroidal mineralocorticoid receptor antagonist, has gained recent approval for treating cardiovascular and kidney-related conditions. Herein, an innovative fluorescence chemo sensor was developed for the determination of finerenone in the pharmaceutical dosage form and the plasma matrix. The method is basically based on chemical transformation of finerenone into a fluorescent product through sequential reactions. This transformation occurs through a sequence of steps involving the interaction of finerenone with trimethylamine, resulting in the formation of a nucleophilic intermediate that subsequently reacts with bromoacetyl bromide to form fluorescent product, (S)-N-(2-bromoacetyl)-4-(4-cyano-2-methoxyphenyl)-5-ethoxy-2,8-dimethyl-1,4-dihydro-1,6-naphthyridine-3-carboxamide. The formed fluorescent product exhibits defined emission peak at 338 nm when excited at 248 nm. Significant concentration-dependent fluorescence enhancement was obtained enabling precise finerenone determination in the pharmaceutical formulation and plasma matrix. The method was optimized and validated providing sensitive determination over linearity range of 1-200 ng/mL with a lower limit of detection at 0.280 ng/mL. This strategy provides an efficient, economical substitute and straightforward, more sensitive analytical method for finerenone assessment in various matrices, in contrast to the previously published method, high-performance liquid chromatography-tandem mass spectrometry, which is expensive and time-consuming.