Nitrogen and sulfur co-doped graphene quantum dots/nanocellulose nanohybrid for electrochemical sensing of anti-schizophrenic drug olanzapine in pharmaceuticals and human biological fluids.

A nanohybrid prepared from green source (nanocellulose, NC) and nitrogen, sulfur co-doped graphene quantum dots (N, S@GQDs) was prepared for the electrochemical detection of olanzapine (OLZ), atypical antipsychotic primarily used to treat schizophrenia and bipolar disorder. Polar groups on the surface of NC and N, S@GQDs provide more anchoring sites for adsorption of OLZ onto the electrode surface. In addition, it provides high conductivity, good mechanical strength, large surface area, and excellent electrical conductivity. The nanocomposite was characterized morphologically and electrochemically by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), transmission electron microscope (TEM), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and square wave adsorptive stripping voltammetry (SWAdSV). Under the optimized conditions, the modified electrode has a good response in the range of 1.5-90.0 × 10-8 M with LOD of 0.5 × 10-8 M. The proposed electrode offers high sensitivity, selectivity, and reliability towards OLZ detection. The SWAdSV was used to determine OLZ in pharmaceutical tablets, human plasma and urine with good recoveries % and reasonable RSD% values.

Segmental hair analysis of olanzapine and N-desmethyl-olanzapine in postmortem hair from mentally ill patients by LC-MS/MS.

Hair analysis is a useful tool for establishing long-term drug intake. Segmental analysis, in particular, where the hair is cut into defined segments, can potentially provide a calendar of patients' drug intake as drugs are incorporated into the growing hair through the bloodstream with an average growth rate of 1 cm per month. Forensic investigations of hair require knowledge of typical concentrations of common pharmaceuticals in hair, which are rarely reported. The aim of this study was to provide values for olanzapine and N-desmethyl-olanzapine concentrations in postmortem hair from chronic olanzapine consumers to contribute to the establishment of a reference interval for this drug. We analyzed postmortem head hair samples from 37 suspected mentally ill patients, who were part of the SURVIVE population, a Danish national autopsy-based study. Each sample was cut into 1 cm segments, and up to six segments, corresponding to up to six months of hair growth prior to death, were analyzed depending on the hair length. The hair extracts were analyzed by liquid chromatography tandem mass spectrometry. Olanzapine and N-desmethyl-olanzapine were added to a published and validated method. The 37 patients were 12 females and 25 males aged 25-81 years. Their hair colors varied from blond to black, with the majority brown, thus no trend could be discerned from the hair colors. Drugs other than olanzapine were found in all cases except one, and illicit drugs were found in the hair samples of 38 % of the cases. We report olanzapine concentrations ranging from 0.005-20.9 ng/mg (median 0.128 ng/mg) and N-desmethyl-olanzapine concentrations from 0.027 to 0.187 ng/mg (median 0.068 ng/mg) for all 141 analyzed segments. Metabolite-to-drug ratios ranged from 0.010 to 3.31 (median 0.590). Dose calculations based on prescription pick-up demonstrated no correlation with the concentrations in hair, but olanzapine concentrations in the proximal hair segment correlated significantly with olanzapine concentrations in postmortem blood. Olanzapine concentrations decreased considerably from the proximal to distal segments, emphasizing the importance of reporting the length of the measured hair when reporting drug concentrations in hair. This study can contribute to the establishment of a reference interval for olanzapine and N-desmethyl-olanzapine concentrations in hair by reporting concentrations in hair from chronic consumers.

Dual Fluorescence-colorimetric Silver Nanoparticles Based Sensor for Determination of Olanzapine: Analysis in Rat Plasma and Pharmaceuticals.

The present work describes a dual-readout assay for the determination of an antipsychotic drug olanzapine using Rhodamine B modified silver nanoparticles (AgNPs). AgNPs, when mixed with Rhodamine B, quenched its fluorescence emission with high quenching efficiency as evident from the Stern Volmer plot. Transmission electron microscopy image and Dynamic Light Scattering histogram of Rhodamine B bound AgNPs showed a stable monodispersed nanosuspension. Addition of olanzapine to Rhodamine B-bound AgNPs resulted in reappearance of fluorescence, which was dependent on the amount of olanzapine added to the system. Besides displacing the surface bound Rhodamine B molecules, it caused aggregation of AgNPs which formed the basis of dual-readout sensor. Several parameters such as pH, reaction time and order of addition of the three components which may influence the analytical signal were studied and optimized. The method was validated for linearity, sensitivity, selectivity, accuracy, precision and recovery. Based on this dual-readout system, linear concentration range was established from 0.05 to 10 µM (fluorescence measurement) and 5.0 to 50 µM (colorimetric response) for olanzapine. The limit of detection (LOD) using fluorescence and colorimetric approach was 0.013 µM and 1.25 µM, respectively. The proposed method showed excellent selectivity for olanzapine in presence of several antipsychotic drugs, cations, sugars and amino acids. Finally, the method was successfully applied to a pharmacokinetic study of olanzapine in rats and also for analyzing pharmaceutical formulations.

Development and validation of solid-phase extraction coupled with a liquid chromatography-tandem mass spectrometry method for quantitation of olanzapine in saliva.

Olanzapine is one of the most commonly used drugs for the treatment of schizophrenia and depression of various origins. Its levels are usually measured in the blood, but the collection of this diagnostic material poses many problems. Therefore, we aimed to develop a fast and sensitive method to determine olanzapine levels in saliva, an easily available diagnostic material. To reduce the consumption of toxic solvents during analyte extraction from saliva, olanzapine was isolated by solid-phase extraction using Oasis® MCX cartridges. Chromatographic analysis was performed by LC-MS/MS, with C18 resin in Atlantis® T3 column as the stationary phase and 2 mM ammonium formate and acetonitrile as the mobile phase (flow rate of 0.25 mL/min, with elution gradient). The specificity, linearity, sensitivity, precision, accuracy, and stability of the optimized method were validated. The relative standard deviation for intra-day precision for three tested olanzapine concentrations did not exceed 12.7%; the highest accuracy value was 113.9%. The recoveries from spiked saliva samples were greater than 87.3% for the two olanzapine concentrations studied. The developed method was then used to determine olanzapine levels in human saliva obtained from 15 patients treated with different doses of olanzapine.

A case of complex suicide due to acute nicotine intoxication caused by cigarette ingestion.

This paper presents an unusual complex suicide case that died of nicotine addiction. The deceased was a 40-year-old male who was found lying dead on the floor in his room. In external findings, many incision wounds on his forearms and skin discoloration with epidermolysis on his cervical region could be seen. In the room, a blood-stained scissors and electric cord hanged on the exercise bike were found. Moreover, nine cigarette residues which were only the filter part and empty bottle of coffee were found on his side. At autopsy, we found that those injuries were not serious enough to lead him to the death. Toxicologically, caffeine, nicotine, cotinine, mirtazapine, and olanzapine could be detected, and the concentrations of nicotine were 3.740, 2.140, 3.100, and 451.100 µg/ml in cardiac blood, peripheral blood, urine, and stomach contents, respectively. These concentrations were evaluated as the fatal levels, and the cause of his death was diagnosed as acute nicotine intoxication.

Reference Brain and Blood Concentrations of Olanzapine in Postmortem Cases.

The antipsychotic drug olanzapine may be subject to postmortem redistribution. This complicates the toxicological evaluation in postmortem cases and a supplementary analysis of brain tissue may be an advantage. We report reference brain and blood concentrations of olanzapine from 40 forensic autopsy cases. Each case was assigned to one of three groups according to the cause of death: (A) fatal intoxication by olanzapine alone; (B) fatal intoxication by olanzapine in combination with other drugs and (C) olanzapine was not related to the cause of death. Quantification of olanzapine in brain and blood was performed by ultra-performance liquid chromatography with tandem mass spectrometry using a validated method. A linear correlation between concentrations in blood and brain from 40 cases was found with a correlation coefficient of 0.87. The median brain:blood ratio was 2.5 (10-90%: 1.2-5.8, range: 0.72-10.4). For the A cases (n = 2), the concentrations in brain (Br) and femoral blood (FB) were: Br: 2.1-3.6 mg/kg, FB: 0.99-1.2 mg/kg; for the B cases (n = 17) the 10-90% were: Br: 0.27-1.0 mg/kg (range: 0.13-1.3 mg/kg) FB: 0.11-0.57 mg/kg (range: 0.096-0.65 mg/kg) and the 10-90% of the C cases (n = 21): Br: 0.05-0.49 mg/kg (range: 0.040-0.87 mg/kg) FB: 0.02-0.14 mg/kg (range: 0.008-0.15 mg/kg). These results can serve as reference concentrations for the interpretation of postmortem forensic cases.

Exploring Ion Suppression in Mass Spectrometry Imaging of a Heterogeneous Tissue.

In this study we have explored several aspects of regional analyte suppression in mass spectrometry imaging (MSI) of a heterogeneous sample, transverse cryosections of mouse brain. Olanzapine was homogeneously coated across the section prior to desorption electrospray ionization (DESI) and matrix-assisted laser desorption ionization (MALDI) mass spectrometry imaging. We employed the concept of a tissue extinction coefficient (TEC) to assess suppression of an analyte on tissue relative to its intensity in an off tissue region. We expanded the use of TEC, by first segmenting anatomical regions using graph-cuts clustering and calculating a TEC for each cluster. The single ion image of the olanzapine [M + H]+ ion was seen to vary considerably across the image, with anatomical features such as the white matter and hippocampus visible. While trends in regional ion suppression were conserved across MSI modalities, significant changes in the magnitude of relative regional suppression effects between techniques were seen. Notably the intensity of olanzapine was less suppressed in DESI than for MALDI. In MALDI MSI, significant differences in the concentration dependence of regional TECs were seen, with the TEC of white matter clusters exhibiting a notably stronger correlation with concentration than for clusters associated with gray matter regions. We further employed cluster-specific TECs as regional normalization factors. In comparison to published pixel-by-pixel normalization methods, regional TEC normalization exhibited superior reduction ion suppression artifacts. We also considered the usefulness of a segmentation-based approach to compare spectral information obtained from complementary modalities.