Spectrophotometric Determination of Nitrazepam in Pharmaceutical Tablets Using Flow Injection Analysis


Nitrazepam (NZP) was determined spectrophotometrically in the pure form and in thepharmaceutical tablets using flow injection analysis (FIA). The method was based on oxidative coupling organicreaction of reduced NZP with promethazine hydrochloride in the presence of sodium periodate to give a greensolution having an absorbance maximum at 613 nm. The various chemical and physical variables were optimized.The calibration graph of NZP is linear from 1 to 50 μg mL-1 with detection limit (S/N = 3) was 0.9284 μg mL-1.The method was successfully applied to the analysis of NZP in pharmaceutical tablets. The results obtained byapplying the proposed FIA method were in good agreement with those obtained by British Pharmacopoeia methodat the 95% confidence.