Use of charge transfer complexation reaction for the spectrophotometric determination of bupropion in pharmaceuticals and spiked human urine

This is the first report on use of two visible spectrophotometric methods for the determination of bupropion hydrochloride (BUPH) in pharmaceuticals and spiked human urine. Bupropion is a second-generation antidepressant agent which is also used in the management of smoking cessation. The methods are based on charge transfer complexation reaction of bupropion base (BUP) as n-electron donor with either p-chloranilic acid (PCA) or 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as π-acceptors to give highly colored radical anion species. The colored products were quantified spectrophotometrically at 520 and 585 nm in PCA and DDQ methods, respectively. Under the optimized experimental conditions, Beerûs law is obeyed over the concentration ranges of 21.7-217 μg mL-1 and 5.65-67.8 μg mL-1 BUP for PCA and DDQ methods, respectively. The molar absorptivity, Sandell sensitivity, detection and quantification limits are also reported. The proposed methods were applied successfully to the determination of BUPH in pure form, commercial tablets and spiked human urine with good accuracy and precision. Statistical comparison of the results was performed with regard to accuracy and precision using Studentûs t-test and F-ratio at 95% confidence level. There is no significant difference between the reference and proposed methods with regard to accuracy and precision. Further, the validity of the methods was confirmed by recovery studies via standard addition technique.