A simple, sensitive and reliable LC-MS/MS method for the determination of 7-bromo-5-chloroquinolin-8-ol (CLBQ14), a potent and selective inhibitor of methionine aminopeptidases: Application to pharmacokinetic studies.

CLBQ14 is an 8-hydroxyquinoline analogue that inhibits methionine aminopeptidase (MetAP), an enzyme responsible for the post-translational modification of several proteins and polypeptides. MetAP has been validated as druggable target for some infectious diseases, and its inhibitors have been investigated as potential therapeutic agents. In this study, we developed and validated a liquid chromatography tandem-mass spectrometry (LC-MS/MS) method for the quantification of CLBQ14 in solution, and in rat plasma and urine. This method was applied to the pharmacokinetic evaluation of CLBQ14 in adult male Sprague Dawley (SD) rats. Chromatographic separation was achieved using an ultra-high-performance liquid chromatography (UHPLC) system equipped with Waters XTerra MS C18 column (3.5 µm, 125 Å, 2.1 × 50 mm) using 0.1% formic acid in acetonitrile/water gradient system as mobile phase. Chromatographic analysis was performed with a 4000 QTRAP® mass spectrometer using MRM in positive mode for CLBQ14 transition [M + H]+m/z 257.919 → m/z 151.005, and IS (clioquinol) transition [M + H]+m/z 305.783 → m/z 178.917. CLBQ14 was extracted from plasma and urine samples by protein precipitation. The retention times for CLBQ14 and IS were 1.31 and 1.40 min respectively. The standard curves were linear for CLBQ14 concentration ranging from 1 to 1000 ng/mL. The intra-day and inter-day accuracy and precision were found to be within 15% of the nominal concentration. Extraction recoveries were >96.3% and 96.6% from rat plasma and urine respectively, and there was no significant matrix effect from the biological matrices. CLBQ14 is stable in samples subjected to expected storage, preparation, and handling conditions. Pharmacokinetic studies revealed that CLBQ14 has a bi-exponential disposition in SD rats, is extensively distributed with a long plasma half-life and is eliminated primarily by liver metabolism.

Effect of chronic antipsychotic treatment on brain structure: a serial magnetic resonance imaging study with ex vivo and postmortem confirmation.

BACKGROUND: There is increasing evidence that antipsychotic (APD) may affect brain structure directly. To examine this, we developed a rodent model that uses clinically relevant doses and serial magnetic resonance imaging (MRI), followed by postmortem histopathological analysis to study the effects of APD on brain structures. METHODS: Antipsychotic , haloperidol, and olanzapine were continuously administered to rats via osmotic minipumps to maintain clinic-like steady state levels for 8 weeks. Longitudinal in vivo MRI scanning (T2-weighted) was carried out at baseline, 4 weeks, and 8 weeks, after which animals were perfused and their brains preserved for ex vivo MRI scanning. Region of interest analyses were performed on magnetic resonance images (both in vivo as well as ex vivo) along with postmortem stereology using the Cavalieri estimator probe. RESULTS: Chronic (8 weeks) exposure to both haloperidol and olanzapine resulted in significant decreases in whole-brain volume (6% to 8%) compared with vehicle-treated control subjects, driven mainly by a decrease in frontal cerebral cortex volume (8% to 12%). Hippocampal, corpus striatum, lateral ventricles, and corpus callosum volumes were not significantly different from control subjects, suggesting a differential effect of APD on the cortex. These results were corroborated by ex vivo MRI scans and decreased cortical volume was confirmed postmortem by stereology. CONCLUSIONS: This is the first systematic whole-brain MRI study of the effects of APD, which highlights significant effects on the cortex. Although caution needs to be exerted when extrapolating results from animals to patients, the approach provides a tractable method for linking in vivo MRI findings to their histopathological origins.

Plasma concentrations of chloroquinaldol (Sterosan) after administration of a vaginal tablet.

The systemic absorption and the plasma concentrations of chloroquinaldol have been determined after local application of one vaginal tablet of Sterosan. A peak plasma concentration of 33 ng/ml was determined 12 h after application. A mean absorption of 6.0% of the applied dose was estimated.