Principles and Procedures for Assessment of Acute Toxicity Incorporating In Silico Methods.

Acute toxicity in silico models are being used to support an increasing number of application areas including (1) product research and development, (2) product approval and registration as well as (3) the transport, storage and handling of chemicals. The adoption of such models is being hindered, in part, because of a lack of guidance describing how to perform and document an in silico analysis. To address this issue, a framework for an acute toxicity hazard assessment is proposed. This framework combines results from different sources including in silico methods and in vitro or in vivo experiments. In silico methods that can assist the prediction of in vivo outcomes (i.e., LD50) are analyzed concluding that predictions obtained using in silico approaches are now well-suited for reliably supporting assessment of LD50-based acute toxicity for the purpose of GHS classification. A general overview is provided of the endpoints from in vitro studies commonly evaluated for predicting acute toxicity (e.g., cytotoxicity/cytolethality as well as assays targeting specific mechanisms). The increased understanding of pathways and key triggering mechanisms underlying toxicity and the increased availability of in vitro data allow for a shift away from assessments solely based on endpoints such as LD50, to mechanism-based endpoints that can be accurately assessed in vitro or by using in silico prediction models. This paper also highlights the importance of an expert review of all available information using weight-of-evidence considerations and illustrates, using a series of diverse practical use cases, how in silico approaches support the assessment of acute toxicity.

The clavicle bone as an alternative matrix in forensic toxicological analysis.

Although human blood is the reference medium in the field of forensic toxicology, alternative matrices may be required when traditional specimens are not available, especially in the investigation of cases involving decomposing remains. Clavicle bone may provide an appropriate sample of choice since it can easily be obtained at autopsy after the removal of the breastplate for the inspection of the thoracic viscera. To the author's knowledge, this is the first time that clavicle bone is used as an alternative matrix for the detection of drugs. The present study aimed to investigate the suitability of clavicle bone as an alternative matrix for the detection of opiates. Opiates were assayed using a gas chromatography-mass spectrometry in the selected ion monitoring mode. Morphine-d6, codeine-d6 and 6-MAM-d3 were used as internal standards for the determination of morphine, codeine and 6-MAM, respectively. A GC/MS method was developed and validated for the determination of opiates in clavicle samples. Morphine, codeine and 6-MAM were successfully separated in spiked samples allowing for their detection at low levels without interferences from the matrix. Chromatographic run time was 11 min and the tested linearity ranged from 5 to 500 ng/g (r2 > 0.99) for all analytes. The method was further applied in clavicle samples of drug-related cases. Its validation parameters and the application of the developed method in clavicle samples from drug addicts, prove its suitability for the detection of opiates and potentially other drugs.

Direct urine analysis for the identification and quantification of selected benzodiazepines for toxicology screening.

A simple and rapid LC/MS method with direct injection analysis was developed and validated for the identification and quantification of ten benzodiazepines (flunitrazepam, nordiazepam, diazepam, 7-aminoflunitrazepam, flurazepam, bromazepam, midazolam, alprazolam, temazepam and oxazepam) in human urine using diazepam-d5 as internal standard (IS). The main advantage of the proposed methodology is the minimal sample preparation procedure, as diluted urine samples were directly injected into LC/MS system. Electrospray ionization in positive mode using selected ion monitoring was chosen for the identification and quantification of the analytes. The linear range was 50-1000 ng/mL for each analyte, with square correlation coefficient (r(2))≥0.981. Interday and intraday errors were found to be ≤5.72%. The LC/MS method was applied at ten real samples found initially to be positive and negative, using immunoassay technique. Finally the results were confirmed with GC/MS. The method demonstrates simplicity and fast sample preparation, accuracy and specificity of the analytes which make it suitable for replacement of immunoassay screening in urine avoiding thus false negative/false positive results. Using this method, laboratories may overcome the problem of high cost instrumentation such as LC-MS/MS by providing similar sensitivity and specificity with other methods.

Naphyrone: a "legal high" not legal any more.

Naphyrone, also known as naphthylpyrovalerone and O-2482, is a cathinone derivative that has been recently advertized for purchase on a number of websites. Naphyrone belongs to a new class of "designer drugs" that has emerged on the drugs abuse market and has gained popularity as the new "legal high." Legal highs have been circulating for a number of years in Europe and are becoming popular in the United States. They are affordable, widely available, legal to use and possess, and legal to supply. This review presents any available information about safety profile, clinical data, analytical profile, and legislation of this legal high, which is not legal any more. Any available information has been collected by various literature search engines and the World Wide Web. The structure of naphyrone is similar to that of pyrovalerone, a monoamine uptake inhibitor. This new designer drug does not have a long history of use, so there is little evidence of its long-term effects or on the risks from its use. Because of its similarity to other cathinone derivatives, naphyrone is likely to share the same risks, such as anxiety, paranoia, and overstimulation of the heart and circulatory system. Naphyrone was classified as a controlled drug under the UK Misuse of Drugs Act of 1971 (Amendment No. 2) Regulation 2010.

Migration study of 1,3-butadiene in eye-drop solutions.

The potential deleterious effects of extractables/leachables in pharmaceutical products led the USP, EP, and JP to require extractable and toxicity testing of container/closure systems. To that, a headspace gas chromatography flame ionization detection method was developed and validated for the determination of 1,3-butadiene (1,3-BD) as a potential extractable residue from a pharmaceutical container/closure system into eye-drop solutions. A migration study was further applied in eight eye-drop solutions (currently marketed products) after short- and long-term exposure of these products at various temperatures. This method allows the establishment of safety-qualification thresholds for 1,3-BD being capable of monitoring eye-drop solution products for this residue.