Derivative ultraviolet spectrophotometric determination of dexchlorpheniramine maleate in tablets in presence of coloring agents

Formulation excipients can frequently affect the drug analysis in pharmaceuticals yielding background interference by ultraviolet spectrophotometry. Sample separation procedures to diminish such interferences are usually recommended as sample pre-treatment, however it can be difficult to eliminate them and they can still persist. In addition, these procedures can be time consuming and laborious to perform. Excipients, like dyeing agents can also be present in a formulation and yield color to drug solution. This work reports the successful development of a derivative ultraviolet spectrophotometry for dexchlorpheniramine maleate (DPM) determination in solid dosage forms, in spite of the color imparted to tablets solution. Standard curves obtained by second order derivative ultraviolet spectrophotometry showed linearity with a correlation coefficient of 0.9999 in the concentration range of 9.75–32.5 μg ml⁻¹ DPM in 0.1 mol l⁻¹ sulfuric acid, using zero-peak (ZP) and peak–peak (PP) methods. The average relative standard deviation range was between 0.26% and 1.08% and 0.18% and 0.63% for ZP and PP methods, respectively. Application of the method in tablet samples resulted in coefficients of variation in the range of 0.83–1.40%, and 0.63–0.83% for ZP and PP methods, respectively. Recovery test percentage values obtained were between 96.95% and 105.61% for the tested tablet samples.