Current Pharmaceutical Design - Volume 23, Issue 36, 2017

Background: The scope of forensic toxicology has been tremendously expanded over the past 50 years. From two general sections forensic toxicology can be further classified into 8-9 sections. Methods: The most outstanding improvement in forensic toxicology is the changes brought by instrumental development. The field of forensic toxicology was revolutionized by the development of immunoassay and benchtop GC-MS in the 1980's and LC-MS-MS in 2000's. Detection of trace amounts of analytes has allowed the use of new specimens such as hair and oral fluids, along with blood and urine. Over a longer period of time, continuous efforts have been made to efficiently extract and separate drug and poison from biological fluids. International endeavors to develop high quality standards and guidelines for drugs and poisons in biological specimens and to promote them in order to increase reliability of laboratories are also part of the recent advancement of forensic toxicology. Interpretation of postmortem toxicology encompasses various factors including postmortem redistribution and stability. Results: Considering the recent trend, the interpretation of toxicological results should account for autopsy findings, crime scene information, and related medical history. The fields of forensic toxicology will continuously develop to improve analysis of target analytes from various specimens, quality assurance program, and results interpretation. In addition, the development of analytical techniques will also contribute further advancement of forensic toxicology. Conclusion: The societies of forensic toxicologists, such as TIAFT, will play an important role for the advancement of forensic toxicology by collaborating and sharing ideas between toxicologists from both developed and developing countries.

This manuscript provides an overview for analysts, medical and scientific investigators, and laboratory administrators, the range of factors that should be considered to implement best practice forensic toxicology. These include laboratory influence over the collection of specimens, their proper transport and chain-of-custody before arrival in the laboratory. In addition, the laboratory needs to ensure properly trained staff use suitably validated and documented analytical procedures that meet the intended purpose and type of case in an accredited or suitably quality oriented management system. To assist the investigating officers laboratory results require an interpretation over their possible significance when sufficient details are available over the circumstances of the case. This requires a thorough understanding of the various factors that influence concentrations of substances and ultimately their likely physiological effect. These include consideration of the route of ingestion, influence over chronicity of usage on tissue concentrations and tolerance, possible combined drug effects or likely adverse reactions and consideration of relevant genetic factors that may have influenced pharmacokinetic or pharmacodynamic response.

International agreement concerning validation guidelines is important to obtain quality forensic bioanalytical research and routine applications as it all starts with the reporting of reliable analytical data. Standards for fundamental validation parameters are provided in guidelines as those from the US Food and Drug Administration (FDA), the European Medicines Agency (EMA), the German speaking Gesellschaft fur Toxikologie und Forensische Chemie (GTFCH) and the Scientific Working Group of Forensic Toxicology (SWGTOX). These validation parameters include selectivity, matrix effects, method limits, calibration, accuracy and stability, as well as other parameters such as carryover, dilution integrity and incurred sample reanalysis. It is, however, not easy for laboratories to implement these guidelines into practice as these international guidelines remain nonbinding protocols, that depend on the applied analytical technique, and that need to be updated according the analyst’s method requirements and the application type. In this manuscript, a review of the current guidelines and literature concerning bioanalytical validation parameters in a forensic context is given and discussed. In addition, suggestions for the experimental set-up, the pros and cons of statistical approaches and adequate acceptance criteria for the validation of bioanalytical applications are given.

Background: In the field of forensic toxicology, the quality of analytical methods is of great importance to ensure the reliability of results and to avoid unjustified legal consequences. A key to high quality analytical methods is a thorough method development. Methods: The presented article will provide an overview on the process of developing methods for forensic applications. Results: This includes the definition of the method's purpose (e.g. qualitative vs quantitative) and the analytes to be included, choosing an appropriate sample matrix, setting up separation and detection systems as well as establishing a versatile sample preparation. Conclusion: Method development is concluded by an optimization process after which the new method is subject to method validation.

Background: The analysis of nails as a keratinized matrix to detect drugs or illicit substances has been increasingly used in forensic and clinical toxicology as a complementary test, especially for the specific characteristics of stably accumulating substances for long periods of time. This allows a retrospective investigation of chronic drug abuse, monitoring continuous drug or pharmaceutical use, reveal in utero drug exposure or environmental exposures. Methods: We herein review the recent literature investigating drug incorporation mechanisms and drug detection in nails for forensic toxicological purposes. Results: Mechanisms of drug incorporation have not yet been fully elucidated. However, some research has lately contributed to a better understanding of how substances are incorporated into nails, suggesting three potential mechanisms of drug incorporation: contamination from sweat, incorporation from nail bed and incorporation from germinal matrix. In addition, numerous methods dealing with the determination of drugs of abuse, medications and alcohol biomarkers in nails have been reported in studies over the years. The latter methods could find application in clinical and forensic toxicology. Conclusion: The studies herein reviewed point out how important it is to standardize and harmonize the methodologies (either pre-analytical or analytical) for nails analysis and the optimization of sampling as well as the development of proficiency testing programs and the determination of cut-off values.

Background: The detection of drugs in hair analysis has progressively emerged as a consequence of the enhanced sensitivity of analytical techniques used in forensic toxicology; a greater advantage in using this matrix with respect to classical ones (i.e. urine and blood) is an easier and non-invasive sample collection, even when the careful supervision of law enforcement officers is required to avoid the risk that the sample may be adulterated or replaced. Moreover, according to the length of the hair, the history of drug exposure can be retrospectively monitored from few weeks up to months or years since sample collection. Methods: Through a detailed revision of the existent literature, this manuscript provides information on the proper sample collection, preparation and analysis, as well as pitfalls in forensic hair analysis, and summarizes the wide range of application of this technology, including excessive alcohol drinking, doping, child abuse, and offences linked to drug use. Results: Verification of history of psychotropic drugs, alcohol and doping agents use by hair analysis, hair testing for driving license regranting and drug facilitated crimes, and testing for drugs in hair of children have been reviewed together with recent trends in hair contamination and possibility to disclose use of new psychoactive substances by hair analysis. Conclusion: Hair analysis in forensic toxicology has been quickly emerged and improved in recent years; a deeper knowledge of advantages and limitations of this unique matrix is necessary for a better use in forensic caseworks.

New psychoactive substances (NPS) have emerged in a threatening way in the last decades. They are sold via the internet or head shops with several names (bath salts, Research chemical, RCs, Legal Highs) and forms (pills, tablets, powder...etc.), and are labelled ambiguously to escape governmental legislation. Designer drugs belong to different chemical classes, but cathinones derivatives presented the most prevalent group. In 2013, this group accounted for 30% of NPS seizures in Europe with more than 450 different compounds, including 101 new molecules reported for the first time in 2014. The increased number of NPS as being sold in parallel market has led several countries to adopt different strategies either on individual surveillance of new emerging drugs or more efficiently on generic control regrouping a wide number of isomers and structurally similar compounds. The identification of these substances is a challenge for toxicologists, which requires sensitive and specific analytical methods based on LC-MS/MS or GC-MS. The usefulness of hair as an alternative matrix for prevalence studies was proved since it offers an overview on drug exposure with a large detection window over weeks or even months and years according to the length of the hair strand. However, as for many drugs of abuse, prevalence studies on cathinones derivatives use are still scarce. Self-reported use or case reports provide most of the available data. The aim of this paper is to provide an update review on prevalence and surveillance of synthetic cathinones use conducted by hair analysis, excluding case report.

Lysergic acid diethylamide (LSD) is a powerful hallucinogen, active at very low dosages, with, as a direct consequence, potential difficulties to be detected and quantified in a clinical or forensic context, in body fluids and even more in hair. The aim of this work is to review literature data related to hair analysis of LSD with a particular focus on the main issues encountered in LSD detection in hair. Results of LSD investigation in hair remain difficult to interpret regarding the very sparse data available on LSD concentrations in hair (n=10). The possibility of pubic hair contamination by urine, as well as the lack of data about LSD incorporation and stability in pubic and head hair, further challenges the interpretation of negative or positive results. The absence of LSD in head hair should be carefully considered, as it does not formally exclude LSD consumption. In all cases of positive results, the interpretation of LSD concentrations in hair remains uncertain and it seems utopian to distinguish repeated intake from single exposure using LSD hair concentration values. Furthermore, a positive result in pubic hair cannot be used to formally prove repeated use of LSD, even in the case of a documented recent use of LSD.

The analysis of hair to detect drugs and drugs of abuse is performed in various contexts, including child protection cases, abstinence control programs, and workplace drug testing. This alternative matrix offers several advantages, such as a large detection window (months) and non-invasive collection. Segmental analysis of multiple hair strands for drugs and metabolites has been widely reported in the literature over the past three decades, whereas a review of the literature showed that there are only 26 articles that report the analysis of a single hair. They focus on two approaches: mass spectrometry imaging techniques, which improve the resolution of dating an intoxication or conventional methods, such as gas chromatography mass spectrometry and liquid chromatography tandem mass spectrometry (LC-MS/MS). Improved sensitivity of LC-MS/MS techniques allows the evaluation of drug content in segments of a single hair. However, the units used to express the results vary, and depend on the authors. Following a review of the literature, we present a case that illustrates drug analyses both in a strand of hair and a single hair. In this case of exposure of a child to zuclopenthixol (ZPT), the analysis of ZPT in a single segmented hair by LC-MS/MS strengthened the presumption of a single administration.

Background: Mephedrone (4-methylmethcathinone, 4-MMC), a ring-substituted synthetic cathinone derivative has become established as a permanent illicit drug in the dynamic new psychoactive substances (NPS) scene. Objective: This review summarizes current knowledge on mephedrone concentrations in biological samples from cases of acute intoxications (fatal and non-fatal), pharmacokinetics studies, wastewater and anonymous pooled urine analysis in order to provide an overview of the reliable scientific knowledge on toxicokinetics of mephedrone in humans. Method: The PubMed® database complemented with Google Scholar® was systematically searched to find published cases of mephedrone intoxications. The searches were done using the keyword “mephedrone OR 4- methylmethcathinone” in association to each of the following strategies: i) “intoxication OR poisoning”; ii) “(blood OR serum OR plasma”) OR “urine” OR (“saliva OR oral fluid”) OR “hair”; iii) “forensic toxicology samples”; iv) “wastewater OR sewage OR pooled urine” and v) “toxicity OR death OR fatal”. Results: Since 2010, a total of 97 fatal cases and 57 non-fatal intoxication cases were identified that presented mephedrone concentrations in human biological matrices attributed directly or indirectly to mephedrone. Typical subjects involved were young male with concomitant use of other drugs (psychostimulants, cannabis, alcohol and other depressants). Mephedrone mean blood concentration from fatal cases was 2,663 ng/mL (range 51-22,000 ng/mL), from non-fatal cases was 166 ng/mL (range, 13-412 ng/mL), that resulted in a similar range from data found in controlled studies with no acute toxicity associated (135 ng/mL, range 52-218 ng/mL). Forensic epidemiology studies based on wastewater and anonymous pooled urine analysis point towards similar variations in use (nightclub scene) to those self-reported in surveys and questioners. Conclusion: Mephedrone blood concentrations in cases of fatal intoxications were higher than in non-fatal cases. In both cases, great variability in mephedrone concentration potentially attributable to interindividual differences in pharmacokinetics-pharmacodynamics and poly-drug use complicates the interpretation of the forensic toxicological analysis.

Background: Benzofurans and benzodifurans are two groups of psychoactive substances that had originally been synthesized for research purpose. Benzofurans' structure is quite similar to the known recreational drug 3,4-methylenedioxymethamphetamine together with its active metabolite 3,4-methylenedioxyamphetamine. Benzodifurans are closely related to phenethylamines, but have more hallucinogens effects and much longer duration of action. This study aims to review the accessible evidence-based literature on benzofurans and benzodifurans pharmacology and toxicology. Methods: A literature search on benzofurans and benzodifurans has been conducted using PubMed. We reviewed articles up to February 2017 and also included data from various governmental websites and discussion groups. Results: This review describes the emergent literature that illustrates the chemical composition of these drugs, patterns of use, pharmacology, toxicology, desired and clinical effects, and treatments of patients. It also provides a compilation of case reports. Conclusion: The knowledge regarding usage prevalence, pharmacokinetic and pharmacodynamic profiles, acute toxic effects, the effects desired on patients and drug related mortality attributed to these drugs is still limited. Nowadays, there are no specific guidelines available to treat benzofurans or dibenzofurans intoxications. For that reason, clinical effects should be the base of treatment. Backing exposures analytically confirmed in clinical and forensic cases and reported clinical effects need to be combined with these compounds while monitoring its prevalence.

Background: Drug concentrations obtained from post mortem samples do not necessarily reflect the concentrations at the time of death, and variations of concentration may be observed between different sites and/or different sampling times. These phenomena, collectively termed post mortem redistribution, concern numerous molecules (medications, drugs of abuse, gases, etc.) and can complicate the interpretation of toxicological analyses. Methods: Literature review. Results: The mechanisms that cause these phenomena are complex and often intricate. Certain organs, which concentrate the molecules before death, may release them very early in the vascular sector. The gastrointestinal tract, liver, lungs and myocardium are mainly concerned. Cell autolysis also plays a part in drug release. Furthermore, micro-organisms (mainly bacteria and yeasts) which colonize the organism during putrefaction may cause neoformation and/or the degradation of certain molecules. Lastly, it appears that the physicochemical and pharmacokinetic profile of xenobiotics, notably their lipophilic nature, their ionization state and their volume of distribution may be factors likely to influence redistribution phenomena. Some recommendations concerning anatomic sampling sites, sampling methods and sample storage make it possible to limit these phenomena.