Metabolic Evaluation of Synthetic Opioids on the Example of U-47700 with the Use of In Vitro and In Vivo Methods for Forensic Toxicology Application

Legal highs present a great threat to health, especially in groups of people experimenting with psychoactive substances. The lack of available knowledge on the biotransformation of these substances necessitates symptomatic treatment in the event of intoxication, which, unfortunately, may be ineffective. Opioids, including heroin analogues, such as U-47700, constitute a special group of designer drugs. In this study, a multi-directional approach to trace the biotransformation of U-47700 in living organisms was used. For this purpose, the in silico assessment (ADMET Predictor) was used first and then followed by an in vitro study using human liver microsomes and the S9 fraction. The biotransformation was then followed in an animal model (Wistar rats). Tissues such as blood, brain and liver were collected for analysis. The study was performed using liquid chromatography with tandem mass spectrometry (LC-MS/MS). The obtained results were compared to those obtained from the analysis of autopsy materials (cases analysed in the Toxicology Laboratory of the Department of Forensic Medicine, Jagiellonian University Medical College in Krakow).