Objective: A new, simple and sensitive spectrophotometric method has been developed for the determination of some antidepressant drugs, namely desvenlafaxine (DSV), dapoxetine (DAP) and citalopram (CIT) in pharmaceutical formulations.Methods: The proposed method was based on the formation of yellow colored ion-pair complex between the studied drugs and two sulphonphthalein dyes viz., bromophenol blue (BPB), and bromothymol blue (BTB) in acidic medium. The optimizations of the reaction conditions were investigated. Beer's law limits, Sandell's sensitivity, correlation coefficient, detection, and quantification limits were calculated.Results: The formed complexes showed absorption maxima at 412 nm and 410 nm measured for all the drugs with BPB and BTB, respectively. The Job's method of continuous variations indicated that a single l: l ion-pair complex was formed. Calibration curves were linear over the concentration range of 0.8–11.4, 0.8–6.4 and 0.8–8.0 μg/ml for DSV, DAP and CIT, respectively.Conclusion: The proposed method has been applied successfully for the analysis of the investigated drugs in pure and in their dosage forms. No interference was observed from common excipients present in pharmaceutical formulations. The proposed method is suitable for quality control applications.Keywords: Desvenlafaxine, Dapoxetine, Citalopram, Sulphonphthalein dyes, Extraction spectrophotometry, Pharmaceutical formulation
