Stability of benzodiazepines in hair after prolonged exposure to chlorinated water

Long-Term Stability of Benzodiazepines and Z-Hypnotic Drugs in Blood Samples Stored at Varying Temperatures

Benzodiazepines (BZDs) and Z-drugs are among the most commonly prescribed pharmaceuticals in the world and are considered standard care for various mental illnesses and for the treatment of sleeping and anxiety disorders, alcohol withdrawal, muscle spasms and epilepsy. Some BZDs are not allowed as pharmaceuticals in many countries, and they are used as designer benzodiazepines (DBZDs). All these compounds are typically screened in routine toxicological analyses for forensic purposes. Knowledge of time-dependent decreases in drug concentrations during storage or transport of samples is of considerable significance and allows forensic toxicologists to achieve reliable data, proper interpretation and high-quality results. The aim of this study was to evaluate changes in the amounts of selected BZDs, DBZDs and Z-drugs in blood samples stored at various temperatures. The study involved BZDs (19), DBZDs (3) and Z-drugs (2) spiked into blank blood. Subsequently, the blood samples were stored at various temperatures (room temperature, 4°C, -20°C and -80°C) for up to 6 months. Analyses were performed at 1- to 2-week intervals using liquid chromatography-tandem mass spectrometry. The stability of compounds was evaluated under four temperature conditions over a 6-month period. Some BZDs were stable at all temperatures tested (e.g., diazepam, oxazepam, nordazepam and prazepam) with a degradation rate of only 0-10%. The highest instability was observed for analyte samples kept at room temperature, and the losses in content for some compounds, e.g., lorazepam and chlordiazepoxide, were almost 100%. For other compounds, the stability was clearly different at each tested temperature. To the best of our knowledge, this is one of the first such comprehensive study of the long-term stability of BZDs covering a wide range of different storage temperatures.

A Systematic Review of Metabolite-to-Drug Ratios of Pharmaceuticals in Hair for Forensic Investigations

After ingestion, consumed drugs and their metabolites are incorporated into hair, which has a long detection window, ranging up to months. Therefore, in addition to conventional blood and urine analyses, hair analysis can provide useful information on long-term drug exposure. Meta-bolite-to-drug (MD) ratios are helpful in interpreting hair results, as they provide useful information on drug metabolism and can be used to distinguish drug use from external contamination, which is otherwise a limitation in hair analysis. Despite this, the MD ratios of a wide range of pharmaceuticals have scarcely been explored. This review aims to provide an overview of MD ratios in hair in a range of pharmaceuticals of interest to forensic toxicology, such as antipsychotic drugs, antidepressant drugs, benzodiazepines, common opiates/opioids, etc. The factors influencing the ratio were evaluated. MD ratios of 41 pharmaceuticals were reported from almost 100 studies. MD ratios below 1 were frequently reported, indicating higher concentrations of the parent pharmaceutical than of its metabolite in hair, but wide-ranging MD ratios of the majority of pharmaceuticals were found. Intra- and interindividual differences and compound properties were variables possibly contributing to this. This overview presents guidance for future comparison and evaluation of MD ratios of pharmaceuticals.

Negative hair test result after long-term drug use. About a case involving morphine and literature review

Although it has been accepted by most scientists that drugs circulating in blood are eligible to hair incorporation, this cannot be considered as a general statement. A 42-year old man was found dead in his swimming pool. He was living alone, and seen alive 2 days before by a neighbour. Femoral blood, cardiac blood and hair were collected during body examination. Free morphine was identified in femoral blood at 28 ng/mL, corresponding to his treatment for chronic pain (3 × 5 mg daily for 4 months). However, with a limit of quantitation (LOQ) at 10 pg/mg, segmental hair testing (3 × 1 cm) for morphine was negative. In this paper, the author has reviewed the different factors which can be responsible of this discrepancy. Several variables can influence the detection of a drug in hair and the author has listed reasons that can account for the absence of analytical response in hair after drug administration. The drug may not be incorporated in hair. That is the case for large bio-molecules, such as hormones, which cannot be transferred from the blood capillaries to growing cells of hair. Cosmetic treatments (perming, colouring, bleaching) or environmental aggressions (ultraviolet radiation, thermal application) will always reduce the concentrations. In this case, the lack of morphine detection was attributed to the effects of chlorinated water from the swimming pool. A negative hair result is also a result. However, this can be interpreted in three different ways: 1. the owner of the hair did not take or was not exposed to the specific drug, 2. the procedure is not sensitive enough to detect the drug, or 3. something happened after drug incorporation (cosmetic treatment, environmental influence).

Interpol review of toxicology 2016-2019

This review paper covers the forensic-relevant literature in toxicology from 2016 to 2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/content/download/14458/file/Interpol%20Review%20.Papers%202019.pdf.

Investigation on the 2D-Distribution of Metallic Elements after Hair Dyeing

Long-term use of hair dyes has potential effects on metal content in hair. However, little research dissects the specific distribution and composition variations of the metal after dyeing. In this study, we investigated the morphological change and metallic elements content variation after dyeing. The results showed that the concentration of essential metal elements decreased, among which the Ca, K, and Na decreased sharply even above 50%. As for the heavy metal, the most significant observation is that Pb increased almost by five times after dyeing. Besides, it revealed, using scanning electron microscope coupled with energy-dispersive X-ray spectroscopy (SEM-EDS), that Pb concentrated at the outer layer of the hair. In addition, two-dimensional proton-induced X-ray emission (2D-PIXE) was applied to analyze the distribution of metallic elements along the longitudinal and cross section of the hair. The results showed that Ca and Zn distributed evenly in the hair along the longitudinal and cross section. It is the first time that 2D-PIXE is applied to analyze the metallic distribution in the hair. This method exhibits high sensitivity and can be widely used in the environmental and medical field to analyze the distribution of metallic elements.