Abstract
Present article describes development and validation of stability indicating liquid chromatographic method for quantitative determination of α-cyclohexyl-α-hydroxy-benzeneacetic acid-4-(diethylamino)-2-butynyl ester hydrochloride a potential antispasmodic and anticholinergic drug and its four impurities (related substances) using a Zorbax SB-Cyano column and mobile phase consisting of aqueous buffer (0.20% triethylamine) and acetonitrile in the ratio 49:51 and with a pH 6.3. The developed LC method was validated with respect to linearity, specificity, accuracy, precision, limit of detection, and limit of quantitation. For the quantitative determination of the impurities, a relative response factor approach was applied with respect to the drug substance. The developed LC method for the related substances and assay determination of drug can be used to evaluate quality of regular production samples. It can also be used to test the stability samples of the drug substance.