Ocular disposition of diazepam in rabbits: understanding its level in vitreous humour for forensic applications

Abstract

The disadvantages associated with routine toxicological samples, such as blood samples, have encouraged the forensic toxicologist to use vitreous humour as an alternative matrix. However, its use is still limited. The reason for this is the lack of a systematic study in this domain. Moreover, the phenomena of drug disposition in ocular tissues are mostly unexplored. This paper presents a controlled study to investigate the distribution of diazepam in post-mortem blood, vitreous humour and ocular tissues using rabbit as an animal model. This study reveals that diazepam levels in vitreous and aqueous humour increase with their decrease in whole blood at post-mortem. A further study on the distribution of diazepam in ocular tissues reveals that the anterior and posterior segment tissues might be responsible for the increase in diazepam levels in aqueous humour and vitreous humour respectively. The present study strengthens the possibility of using vitreous humour as a complementary sample to blood in forensic toxicological investigations.

Keywords:

• forensic science
• forensic toxicology
• vitreous humour
• ocular tissues

Acknowledgements

The authors would like to thank the Directorate of Forensic Science Services for providing financial grant (DFS/15(1)/(2)/2003/EMR) for this study. The first author would like to thank the Council of Scientific and Industrial Research (CSIR), New Delhi for providing Senior Research Fellowship.