HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY OF BENZODIAZEPINES .1. STABILITY-INDICATING ASSAY OF DIAZEPAM TABLETS

A high‐performance liquid chromatographic procedure was developed for diazepam tablet analysis. This procedure separates the manufacturing intermediate, 7‐chloro‐1,3‐dihydro‐5‐phenyl‐2H‐1,4‐benzodiazepin‐2‐one, and the decomposition products, 3‐amino‐6‐chloro‐1‐methyl‐4‐phenylcarbostyril and 2‐melhylamino‐5‐chlorobenzophenone, from diazepam. The liquid chromatographic procedure is superior to the USP UV assay because it is stability indicating. The method is simple, accurate, and fast, involving only one extraction step. A reversed‐phase column and a methanol‐water mobile phase were used. Under these conditions, 0.1% of the decomposition products was detectable. Typical samples of diazepam tablets showed no degradation. Copyright © 1979 Wiley‐Liss, Inc., A Wiley Company