Utility of Chromogenic Properties of P-Dimethylaminobenzaldehyde for Determination of Certain Anti-Depressant Drug in Bulk, Pharmaceutical Preparation and Application to Tablets Uniformity Testing

Abstract

Simple, sensitive, accurate, and precise spectrophotometric assay has been developed and validated for the determination of selected anti-depressant drug namely; Milnacipran HCl (MCN) in pure form and pharmaceutical formulation. The method was based on the reaction of methanolic solution of selected anti-depressant drug with p-dimethylaminobenzaldehyde in acidic medium which give yellow product that can be determined at λex = 400 nm. The optimization of the reaction conditions such as the type of solvents, reagent concentration and reaction time were investigated. Under the optimum conditions, beer’s law is obeyed in the concentration range 60-300 μg mL-1, with good correlation coefficient (r² ≥ 0.998) and with a standard deviation (RSD% ≤ 0.0095). The limits of detection & the limits of quantification were found to be 13.1 and 40.0 μg mL-1, respectively. A Job’s plot of the absorbance versus the molar ratio of MCN to p-dimethylaminobenzaldehyde under consideration indicated (1:1) ratio. The method were successfully applied to the determination of MCN in its pharmaceutical formulation and the results obtained by the proposed method for the pure MCN and commercial tablets agreed well with those obtained by the reported method.