Stability - indicating methods for the determination of lorazepam, delorazepam and tetrazepam

Two simple, rapid and accurate techniques have been developed for the determination of lorazepam, delorazepam and tetrazepam in the presence of their degradation products. The first one depends on the derivative ratio spectrophotometry while the second depends on spectrodensitometry. The validity of the proposed procedures was proved using standard addition technique and laboratory-prepared mixtures of the drugs and their degradation products. The proposed procedures were successfully applied for the drugs analysis in their tablet dosage form