Benzodiazepines (BZD) represents an important class of compounds of a wide range of pharmacological effects and therapeutic uses. This project discusses the classification, mechanism of action, major pharmacological effects and adverse reactions of BZD. It also reports on the chemical synthesis and important physicochemical properties of BZD. The influence of the chemical structure’s modification of BZD upon drug's potency, physicochemical characteristics, pharmacokinetics and drug metabolism were elucidated. A problem of drug abuse of BZD either alone or in combination with other central nervous system (CNS) depressants was reviewed. Forensic analysis of BZD in biological samples for screening and confirmation of BZD abusers in forensic settings was demonstrated and the most important analytical techniques used for screening and measurement of BZD in forensic laboratory were described. In this project, selected gas chromatography-mass spectrometry (GC-MS) and Liquid Chromatography- Tandem Mass Spectrometry (LC-MS/MS) spectra of diazepam (MS lab, Prof M. Abdel-Hamid) for confirmation and quantitation of diazepam are presented.
BZD are a group of chemically synthetic compounds that were firstly synthesized in late fifties. BZD share a common chemical structure features and their importance comes with relation to their effect on the CNS. BZD are known best to work by depressing the central nervous system and show an important role being used for several purposes such as, hypnotics, sedatives, antiepileptics and muscle relaxants. The emergence of benzodiazepines seemed to be very helpful due to their potent effect and low toxicity compared to barbiturates. Although being relatively safe compounds, drug dependence and tolerance problems can still arise with their use in clinics. Although sharing important chemical structure features (figure 1), BZD still show some differences that give each compound its unique characteristics and clinical uses (table 1). Due to difference in their chemical structures, BZD may have some variations in their medical use e.g. flunitrazepam and oxazepam are used as hypnotics and sedatives, however, triazolam and diazepam are used as anxiolytics and muscle relaxants. Alprazolam, however, known be used as an antidepressant, whereas BZD including diazepam and clonazepam are clinically prescribed as antiepileptics. This research assay will include an overview of representative examples of BZD (fig. 2), important physical and chemical characteristics, pharmacology, disposition, abuse and toxicological parameters, and important principles of analysis.
Figure 1: The general chemical structure of benzodiazepines, Adapted from (19)
Table 1: Chemical functional groups of selected BZD, Adapted from (19)
Compounds R1 R2 R3 R4
Diazepam Cl CH3 H -
Temazepam Cl CH3 H 3:OH
Fludiazepam Cl CH3 F -
Diapotassium Clorazepate Cl H H 3:CHOOK
Medazepam Cl CH3 H 2:CH2
Clordiazepoxide Cl - H 2:CNHCH3;4:NO...