Bioanalytical LC-QTOF/MS Method for a N-phenylpiperazine Derivate (LQFM05): An Anxiolytic- and Antidepressant-like Prototype Drug Applied to Pharmacokinetic and Biodistribution Studies.

The LQFM05 is a prototype drug designed for treatment of psychiatric disorders, such as schizophrenia, exhibiting anxiolytic- and antidepressant-like (12 or 24 µmol/kg) effects in classical behavioral tests. In order to evaluate its pharmacokinetic properties, a liquid chromatography method coupled to a quadrupole time of flight mass spectrometry system (LC-QTOF/MS) was developed and fully validated for LQFM05 analysis in rat plasma and tissue samples (brain, heart, liver, and kidneys). Liquid-liquid extraction, solid phase extraction and protein precipitation were assessed as clean-up procedures for biological samples and analyte enrichment. Plasma and tissue samples underwent protein precipitation as a preliminary step, using acetonitrile. Linearity was fully demonstrated for the dynamic range (10.0 to 900.0 ng/mL), with r2 values higher than 0.99 (RSDslope ≤ 2%, Fcal < Ftab, Ccal < Ctab). Biodistribution studies in rats revealed high brain tissue concentrations (12.4 µg/g), suggesting elevated drug affinity to the main therapeutic target tissue, showing a blood partition coefficient of 1.9. Kidneys also showed great exposure and tissue affinity, suggesting a potential extrahepatic clearance. Likewise, all examined tissues exhibited satisfactory LQFMF05 distribution. The mass fragmentation spectrum indicated the presence of its main metabolite, LQFM235, yielded by high hepatic hydroxylation route, an equally bioactive derivative. Lastly, the developed LC-QTOF/MS method was shown to be sensitive (LOQ = 10 ng/mL), precise and accurate for LQFM05 determination in tissue homogenates and plasma samples.

Fatal metaldehyde poisoning in a dog confirmed by gas chromatography.

BACKGROUND: Metaldehyde is a toxic pesticide used mainly as a molluscicide, responsible for intoxication and deaths in both humans and animals. Accidental exposure to metaldehyde in dogs is considered rare, but severe. Data concerning clinical and veterinary forensic toxicology are largely incomplete, especially regarding case reports in dogs. The present work reports a complete and detailed description of a case from the history, clinical evolution, pathological exams and toxicological diagnosis in an accidental case of metaldehyde poisoning in dog. CASE PRESENTATION: An eleven-month-old, 3.0 kg, male German Spitz was presented for emergency care with acute vomiting and seizures 3 hours after suspected accidental ingestion of commercial molluscicide containing 3% metaldehyde (Lesmax®). The animal was in lateral recumbency and showed stuporous mentation, salivation, tonic-clonic status epilepticus, systemic tremors, bilateral miosis, absent palpebral, corneal, oculovestibular and gag reflexes, severely depressed spinal reflexes, dyspnea and tachycardia. Despite treatment, the patient progressed to comatose mentation and died. Necropsy examination revealed discrete lesions in the liver and central nervous system, while stomach examination revealed content of feed, activated charcoal and blue-green granules, compatible to the commercial formula of metaldehyde. Histology examination revealed extensive hemorrhage and severe centrolobular necrosis of the liver and tumefaction of Kupfer cells. Brain samples showed discrete hemorrhage and hyperemia. In order to confirm the diagnosis, samples from feces, stomach content, spleen, liver, heart, kidneys and brain were submitted gas chromatography analysis. Results confirmed the presence of metaldehyde in all samples. We describe clinicopathological abnormalities of a fatal case of metaldehyde poisoning in a dog, as well as postmortem diagnosis using gas chromatography. CONCLUSION: Metaldehyde poisoning is rarely reported, since the diagnosis is often difficult and the notifications scarce. To our knowledge, this is the first report describing clinical signs, pathological findings and chromatographic diagnosis. This report aims to contribute to the understanding of the pathogenesis of metaldehyde intoxication, to further explore veterinary forensic toxicology diagnosis.

Thin layer chromatography coupled to paper spray ionization mass spectrometry for cocaine and its adulterants analysis.

Thin layer chromatography (TLC) is a simple and inexpensive type of chromatography that is extensively used in forensic laboratories for drugs of abuse analysis. In this work, TLC is optimized to analyze cocaine and its adulterants (caffeine, benzocaine, lidocaine and phenacetin) in which the sensitivity (visual determination of LOD from 0.5 to 14mgmL(-1)) and the selectivity (from the study of three different eluents: CHCl3:CH3OH:HCOOHglacial (75:20:5v%), (C2H5)2O:CHCl3 (50:50v%) and CH3OH:NH4OH (100:1.5v%)) were evaluated. Aiming to improve these figures of merit, the TLC spots were identified and quantified (linearity with R(2)>0.98) by the paper spray ionization mass spectrometry (PS-MS), reaching now lower LOD values (>1.0µgmL(-1)). The method developed in this work open up perspective of enhancing the reliability of traditional and routine TLC analysis employed in the criminal expertise units. Higher sensitivity, selectivity and rapidity can be provided in forensic reports, besides the possibility of quantitative analysis. Due to the great simplicity, the PS(+)-MS technique can also be coupled directly to other separation techniques such as the paper chromatography and can still be used in analyses of LSD blotter, documents and synthetic drugs.

A survey of adulterants used to cut cocaine in samples seized in the Espírito Santo State by GC-MS allied to chemometric tools.

Cocaine is a stimulant drug of the central nervous system (CNS) extracted from the leaves of Erytroxylum coca. It is defined as a tropane alkaloid containing 1R-(exo,exo)-3-(benzoyloxy)-8-methyl-8-azabicyclo[3.2.1]octane-2-carboxylic acid methyl esther. However, despite its defined composition, a wide variety of chemical additives are present in cocaine found in the illicit market, such as benzocaine, lidocaine, caffeine, procaine and phenacetin. In this work, 512 cocaine samples seized by the Civil Police of Espirito Santo state (PC-ES, Brazil) were analyzed by gas chromatography mass spectrometry (GC-MS) allied to principal component analysis (PCA) in order to classify the samples as a function of seizure year (2008, 2009, 2010, 2011 and 2012) and location (metropolitan, north, south and central). The cocaine content (wt.%) and its adulterants were also estimated. Analyzing the samples seized between 2008 and 2011, three sample sets are clearly grouped according to the degree of adulteration with caffeine and lidocaine: 100-50 wt.% of cocaine; 50-20 wt.% of cocaine; and 20-80 wt.% of lidocaine and 60-80 wt.% of caffeine, simultaneously. The last group is formed by samples seized between 2008 and 2009, which proves the higher degree of adulteration during this period. In 2012, higher cocaine content was observed for the 191 analyzed samples than in samples from previous years. The PCA data also suggests that the metropolitan region samples had a higher degree of adulteration than the state countryside samples.