Spectrophotometric assay of clorazepate dipotassium in dosage forms

A new spectrophotometric method for the determination of clorazepate dipotassium in pure form and in pharmaceutical preparation has been developed. the method is based on the complex formation due to charge transfer between clorazepate dipotassium and alizarin sulphonic acid (sodium salt). the pink coloured complex is obtained after heating the reaction at 50 °c for 90s. it has maximum absorbance at 530 nm and is stable for more than 24 hours. the reaction obeys beer's law from 5 to 250 μg/ml of clorazepate dipotassium with 5 μg/ml as the visual limit of quantitation. the molar absorptivity and relative standard deviation are 0.45 × 104 mol-1 cm-1 and 0.94 %,respectively. the quantitative assessment of tolerable amounts of other drugs not interfering was also studied.