In vitro and in vivo metabolic study of three new psychoactive ß-keto-arylcyclohexylamines.

Since the 2000s, an increasing number of new psychoactive substances have appeared on the illicit drug market. ß-Keto-arylcyclohexylamine compounds play important pharmacological roles in anesthesia; however, because these new psychoactive substances have rapidly increasing illicit recreational use, the lack of detailed toxicity data are of particular concern. Therefore, analysis of their metabolites can help forensic personnel provide references and suggestions on whether a suspect has taken an illicit new psychoactive ß-keto-arylcyclohexylamine. The present study investigated the in vitro and in vivo metabolism and metabolites of three ß-keto-arylcyclohexylamines: deschloro-N-ethyl-ketamine, fluoro-N-ethyl-ketamine and bromoketamine. In vitro and in vivo models were established using zebrafish and human liver microsomes for analysis of Phase I and Phase II metabolites by liquid chromatography-high-resolution mass spectrometry. Altogether, 49 metabolites were identified. The results were applied for the subject urine samples of known fluoro-N-ethyl-ketamine consumer screen analysis in forensic cases. Hydroxy-deschloro-N-ethyl-ketamine, hydroxy-fluoro-N-ethyl-ketamine and hydroxy-bromoketamine were recommended as potential biomarkers for documenting intake in clinical and forensic cases.

Metabolism of ADB-FUBIATA in zebrafish and pooled human liver microsomes investigated by liquid chromatography-high-resolution mass spectrometry.

RATIONALE: ADB-FUBIATA is one of the most recently identified new psychoactive substance (NPS) of synthetic cannabinoids. The co-use of in vitro (human liver microsomes) and in vivo (zebrafish) models offers abundant metabolites and may give a deep insight into the metabolism of NPS. METHODS: In vivo and in vitro metabolic studies of new synthetic cannabinoid ADB-FUBIATA were carried out using zebrafish and pooled human liver microsome models. Metabilites were structurally characterized by liquid chromatography-high-resolution mass spectrometry. RESULTS: In total, 18 metabolites were discovered and identified in the pooled human liver microsomes and zebrafish, including seventeen phase I metabolites and one phase II metabolite. The main metabolic pathways of ADB-FUBIATA were hydroxylation, dehydrogenation, N-dealkylation, amide hydrolysis, glucuronidation, and combination thereof. CONCLUSION: Hydroxylated metabolites can be recommended as metabolic markers for ADB-FUBIATA because of the structural characteristics and high intensity. These metabolism characteristics of ADB-FUBIATA were useful for its further forensic or clinical related investigations.

Health risk assessment for human mercury exposure from Cinnabaris-containing Baizi Yangxin Pills in healthy volunteers Po administration.

BACKGROUND: Cinnabaris (α-HgS), a mineral traditional Chinese material medica, has been used in combination with other herbs manifesting some definite therapeutic effects for thousands of years. But the currently reported mercury poisoning incidents raised the doubts about the safety of Cinnabaris-containing traditional Chinese medicines (TCMs). Baizi Yangxin Pills (BZYXP) is a Cinnabaris-containing TCM widely used in clinical practice. This study evaluated the health risk of mercury exposure from BZYXP in healthy volunteers based on the total mercury and mercury species analysis of blood and urine after single and multiple doses of BZYXP. METHODS: Blood pharmacokinetics and urinary excretion studies of mercury were compared between single (9 g, once daily) and multiple doses (9 g, twice daily, continued for 7 days) of BZYXP. The whole blood and urine samples were collected at the specific points or periods after the administration of BZYXP. The total mercury and mercury species in blood and urine samples were determined by cold vapor-atomic fluorescence spectrometry (CV-AFS) and HPLC-CV-AFS, respectively. RESULTS: The mercury was excreted slowly and accumulated obviously after continuous exposure of BZYXP. Moreover, the well-known neurotoxin methylmercury (MeHg) was detected in blood samples after 7 days' administration of BZYXP. In the urine samples, only Hg(II) was detected. Therefore, long-term use of BZYXP will cause mercury poisoning due to mercury's high accumulative properties and MeHg formation. CONCLUSION: Cinnabaris-containing TCMs such as BZYXP should be restricted to cases in which alternatives are available, and the blood mercury species profile should be monitored during the long-term clinical medication.

Kelp as a biomonitor of persistent organic pollutants in coastal areas of China: Contamination levels and human health risk.

Kelp, the brown alga distributed in coastal areas all over the world, is also an important medicine food homology product in China. However, the levels and profiles of persistent organic pollutants (POPs) in kelp have not been thoroughly investigated to date. Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and emerging bromine flame retardants (eBFRs) were evaluated in 41 kelp samples from the main kelp producing areas in China. The concentrations of total PCBs, PBDEs and eBFRs were in the range of 0.321-4.24 ng/g dry weight (dw), 0.255-25.5 ng/g dw and 3.00 × 10-3-47.2 ng/g dw in kelp, respectively. The pollutant pattern was dominated by decabromodiphenyl ethane (DBDPE, 13.0 ± 11.7 ng/g dw) followed in decreasing order by BDE-209 (2.74 ± 4.09 ng/g dw), CB-11 (1.32 ± 1.06 ng/g dw). The tested results showed that kelp could reflect the pollution status of PCBs, PBDEs and eBFRs, indicating the suitability of kelp as a biomonitor of these harmful substances. Finally, the data obtained was used to evaluate human non-cancer and cancer risks of PCBs and PBDEs via kelp consumption for Chinese. Though the calculated risk indices were considered acceptable according to the international standards even in the worst scenarios, the POPs levels in kelp should be monitored continuously as a good environmental indicator.

Identification of degradation products of brivaracetam using liquid chromatography quadrupole time-of-flight tandem mass spectrometry: Degradation pathway elucidation.

RATIONALE: Pyrrolidone-based drugs find widespread use in treating conditions such as epilepsy and Alzheimer's disease, and in various other medical applications. Brivaracetam, the latest generation of pyrrolidone drugs, has exhibited significant promise owing to chemical structure modifications. Its affinity to the SV2A receptor is double that of the previous-generation drug, levetiracetam. Consequently, brivaracetam holds substantial potential for diverse applications. As a novel drug not yet included in the pharmacopeias of developed nations, comprehensive analysis and research are necessary to guarantee its safe utilization in clinical settings. METHODS: A liquid chromatography quadrupole time-of-flight tandem mass spectrometry (LC/QTOFMS) method has been developed to effectively separate, identify and characterize both the degradation products and process-related substances of brivaracetam. Stress testing of the sample was carried out following the guidelines outlined in ICH Q1A(R2). The structures of these impurities were identified through positive electrospray ionization QTOF high-resolution MS and NMR spectroscopy. Additionally, the formation mechanism of each degradation product is thoroughly discussed. RESULTS: Under the analytical conditions outlined in this paper, brivaracetam and its degradation products were effectively separated. Thirteen degradation products were detected and characterized, shedding light on their origins and degradation pathways. Among these, three degradation products align with previously reported impurities, and two unreported degradation products were synthesized and confirmed through NMR spectroscopy. The stress testing results revealed the instability of brivaracetam under acidic, alkaline, oxidative and thermal stress conditions, while it exhibited relative stability under photolytic stress conditions. CONCLUSION: The study developed an analytical method for brivaracetam that enabled the effective detection and separation of brivaracetam and its 13 degradation products. This method addresses a gap in both current domestic and foreign drug standards. The structures of all the major degradation products were characterized by high-resolution LC/QTOFMS, which is essential for quality control during the drug production process, stability evaluation and the establishment of proper storage conditions.

Compatibility Study of Peptide and Glycerol Using Chromatographic and Spectroscopic Techniques: Application to a Novel Antimicrobial Peptide Cbf-14 Gel.

The interactions between active pharmaceutical ingredients (APIs) and excipients may lead to API degradation, thereby affecting the safety and efficacy of drug products. Cbf-14 is a synthetic peptide derived from Cathelicidin-BF, showing potential for bacterial and fungal infections. In order to assess impurities in Cbf-14 gel, we developed a two-dimensional liquid chromatography coupled with quadrupole/time-of-flight mass spectrometric method. A total of eleven peptide degradation impurities were identified and characterized. Furthermore, the compatibility tests were conducted to evaluate the interactions of Cbf-14 with glycerol and methylcellulose, respectively. The results revealed that the impurities originated from condensation reactions between Cbf-14 and aldehydes caused by glycerol degradation. Several aldehydes were employed to validate this hypothesis. The formation mechanisms were elucidated as Maillard reactions between primary amino groups of Cbf-14 and aldehydes derived from glycerol degradation. Additionally, the compatibility of Cbf-14 with glycerol from different sources and with varying storage times was investigated. Notably, the interaction products in the gel increased with extended storage time, even when fresh glycerol for injection was added. This study offers unique insights into the compatibility study of peptides and glycerol, contributing to the ongoing quality study of Cbf-14 gel. It also serves as a reference for the design of other peptide preparations and excipients selections.

Analysis of bacitracin and its related substances by liquid chromatography tandem mass spectrometry / 药物分析学报

A suitable liquid chromatography quadrupole time-of-flight mass spectrometric (LC–Q-TOF–MS) method was developed for separation and characterization of related substances in bacitracin test drug. The separation was performed on LiChrospher RP-18 column using methanol as mobile phase A and 0.2% ammonium acetate buffer solution as mobile phase B in gradient elution. A total of 12 related substances were detected through high resolution mass spectrometric determination in a positive electrospray ionization mode. They were identified as co-existing active components and degradation products of bacitracin through the analysis and elucidation of both the protonated parents and the product ions of all the related substances and their fragmentation pathways were also proposed.