Determination of drotaverine hydrochloride from pharmaceutical dosage form by extractive ion pair complex colorimetric method

Simple sensitive and accurate extractive colorimetric method was developed for the estimation of drotaverine hydrochloride in Pharmaceutical dosage forms. The method was based on the formation of colored ion pair complexes by the drugs with thiocynate ions. These ion pair complexes were quantitatively extracted under the experimental condition in chloroform. The absorbance values were measured at 622 nm respectively. The proposed method was validated statistically. A recovery of method was carried out by standard addition methods. The Beer’s law ranges were found to be 2-18 μg∕ml, respectively. The low values of standard deviation and percentage RSD indicate high precision of method. Hence the method is useful for routine estimation of drotaverine hydrochloride in tablets respectively.