Acidic hydrolysis of bromazepam studied by high performance liquid chromatography. Isolation and identification of its degradation products

J Pharm Biomed Anal. 1998 Jun;17(2):327-35. doi: 10.1016/s0731-7085(97)00201-x.


A kinetic study on the acidic hydrolysis of bromazepam was carried out in 0.01 M hydrochloric acid solution at 25 and 95 degrees C. A reversed-phase HPLC method was developed and validated for the determination of bromazepam and its degradation products. Bromazepam degraded by a consecutive reaction with a reversible first step. Two degradation products were isolated and identified by infrared, 1H and 13C nuclear magnetic resonance and mass spectroscopy. Spectroscopic data indicated that N-(4-bromo-2-(2-pyridylcarbonyl)phenyl)-2-aminoacetamide was the intermediate degradation product of this acid hydrolysis, whereas 2-amino-5-bromophenyl-2-pyridylmethanone was the final one. Therefore, the mechanism of this acid-catalysed hydrolysis involved initial cleavage of the 4,5-azomethine bond, followed by slow breakage of the 1,2-amide bond. Statistical evaluation of the HPLC method revealed its good linearity and reproducibility. Detection limits were 3.8 x 10(-7) M for bromazepam, 6.25 x 10(-7) M for the intermediate and 8.16 x 10(-7) M for the benzophenone derivative.

MeSH terms

  • Acetamides / analysis*
  • Animals
  • Anti-Anxiety Agents / analysis
  • Anti-Anxiety Agents / chemistry*
  • Benzophenones / analysis*
  • Bromazepam / analysis
  • Bromazepam / chemistry*
  • Chromatography, High Pressure Liquid
  • Cricetinae
  • Humans
  • Hydrolysis
  • Kinetics
  • Mathematics
  • Middle Aged
  • Molecular Structure
  • Pyridines / analysis*


  • 2-amino-5-bromophenyl-2-pyridylmethanone
  • Acetamides
  • Anti-Anxiety Agents
  • Benzophenones
  • N-(4-bromo-2-(2-pyridylcarbonyl)phenyl)-2-aminoacetamide
  • Pyridines
  • benzophenone
  • Bromazepam