Use of Chemical Reagents in Non-fluorescent Pharmaceutical Labels: A Comprehensive Review

Spectrofluorimetry is an analytical technique with high sensitivity, specificity, and simplicity, and is very economical. Drugs that lack native fluorescence are derivatized with reagents so that highly fluorescent compounds are formed that can be readily detected by spectrofluorimetry. There are different reagents such as 4-chloro-7-nitrobenz-2-oxa-1,3-diazole (NBD-Cl), N- methylnicotinamide chloride (NMNCl), 9-flurenylmethylchloroformate (FMOC-Cl), dansylchloride (DNS-Cl), 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH), 1,2- naphthoquinone-4-sulfonate (NQS), 1,4- benzoquinone, 4-fluro-7-nitrobenzofurazan (NBD-F), ninhydrin, benzoin, N- bromo succinimide (NBS), acetylacetone & HCHO, ortho-phthalaldehyde (OPA), and 2-cyanoacetamide used in spectrofluorimetric determination of the drugs that lack native fluorescence. The present review highlights these reagents with principle, reaction conditions, and their applications.