Spectrophotometric Determination of Nitrazepam in Pharmaceutical Tablets by Oxidative Coupling Reaction with Pyrocatechol


A simple and sensitive spectrophotometric method was developed for the determination of nitrazepam(NZP) in pharmaceutical tablets. The method was based on oxidative coupling organic reaction of reduced NZP withpyrocatechol in the presence of ferric sulfate to form red water soluble product with maximum absorbance at 510 nm.The reaction conditions were studied and optimized. The linear range for the determination of NZP, and the detectionlimit were 1 – 24 ىg mL-1 and 0.698 ىg mL-1, respectively. The proposed method has been appliedsuccessfully for the determination of NZP in pharmaceutical tablets. A statistical comparison of these results withthose obtained by the British pharmacopoeia procedure using the Student t-test and variance ratio F-test shows a goodagreement and indicates no significant difference in accuracy and precision at the 95% confidence.