Development of fluorescence probe for spectrofluorimetric determination of viloxazine hydrochloride in pharmaceutical form and rat plasma; additional pharmacokinetic study

Abstract Attention deficit hyperactivity disorder (ADHD) is a neurological condition frequently identified in early childhood and frequently co‐occurs with other neuropsychological disorders, particularly autism. Viloxazine hydrochloride, a non‐stimulant medication, has recently gained approval for treating attention‐deficit hyperactivity disorder. This paper describes the first spectrofluorimetric method for precisely measuring the content of viloxazine in pharmaceutical capsules and rat plasma. This method employed NBD‐Cl (4‐chloro‐7‐nitrobenzo‐2‐oxa‐1,3‐diazole) as a fluorescent probe, which transformed viloxazine in an alkaline environment into a remarkably sensitive fluorescent adduct. Upon excitation at 476 nm, this adduct becomes detectable at a wavelength of 536 nm. The method was validated using ICH criteria, revealing acceptable linearity across a concentration range of 200–2000 ng/ml and high sensitivity with LOD and LOQ values of 46.774 ng/ml and 141.741 ng/ml, respectively. This method was adeptly applied in a pharmacokinetic study of viloxazine in rat plasma following a single oral dose (10 mg/kg), yielding a mean peak plasma concentration (C max ) of 1721 ng/ml, achieved within 1.5 h. Furthermore, the environmental impact of the technique was assessed using two greenness assessment tools, revealing a notable level of eco‐friendliness and sustainability.