Estimation of Drotaverine hydrochloride by extractive colorimetric Methods in Bulk and Pharmaceutical Dosage Form

Simple sensitive and accurate extractive spectrophotometric methods have developed for the estimation of drotaverine hydrochloride in pharmaceutical dosage form. The methods are based on the formation of coloured complexes by the drug with reagents like bromophenol blue, solochrome dark blue and bromocresol green in acidic medium. The ion associated complexes were formed and quantitatively extracted under the experimental condition in chloroform. The absorbance values were measured at 420 nm, 495 nm and 430 nm respectively. The proposed methods were validated statistically. Recoveries of methods were carried out by standard addition methods. The linearity was found to be 1-9 μg/ml, 2 -16μg/ml, 1-16 μg/ ml for methods 1, 2 and 3 respectively. The low values of standard deviation and percentage RSD indicate high precision of methods. Hence these methods are useful for routine estimation of drotaverine hydrochloride in tablets.