ABSTRACT
@#Cinnabaris(α-HgS) is a mineral traditional Chinese material medica, as a tranquilizer and sedative, which is widely used in combination with herbs for the treatment of children high fever and convulsion.However, a large amount of mercury in Cinnabaris poses a potential risk to the immature central nervous system of children and probably causes severe memory disorders.Inthisstudy,three groups of juvenile rats were given low, medium, and high doses of Cinnabaris by oral gavage once a day for 14 continuous weeks, respectively.The blood mercury concentrations of the rats at different growth phases were monitored by atomic fluorescence spectrometry.The brain structural and functional changes related to the memory functions were investigated through HE staining and Morris water-maze test. Correlation analysis was conducted to clarify the dose- mercury exposure-toxic effect relationship of Cinnabaris and memory disorders.It was found thatthe blood mercury levels increased in both time- and dose-dependent manner.After the 14-week continuous administration of Cinnabaris, the pathological lesions in hippocampal neurons of rats in the high dose group were observed including pyknosis and disordered cell arrangement.In the Morris water-maze test, compared with the control group, rats in the high dose group exhibited the significantly prolonged latency to find the platform and the target quadrant, and the time spent in the target quadrant was obviously shortened. Thus, the significant correlations were established between Cinnabaris dose and mercury exposure,mercury exposure and memory disorders, respectively. In conclusion, the long-term and overdose administration of Cinnabaris in juvenile rats can increase the in-vivo mercury level, destroy the normal hippocampal morphological structure, and lead to memory disorders. This study provided scientific references for the potential mercury poisoning risks pharmacovigilance of Cinnabaris-containing paediatric formulations.
ABSTRACT
@#To establish a method for the determination of formaldehyde and glyoxal simultaneously in varenicline tartrate active pharmaceutical ingredient (API) and its intermediate, formaldehyde and glyoxal were derivatized by 2, 4-dinitrophenylhydrazine (2,4-DNPH) to improve the HPLC retention and UV detection sensitivity. Separation was performed on a C8 (150 mm × 4.6 mm, 5 μm) column by linear gradient elution using acetonitrile and water as the mobile phase; the detective wavelength was set at 380 nm.Formaldehyde and glyoxal were quantitatively determined by an external reference method.Linear calibration was established for both formaldehyde and glyoxal in the range from 0.094 to 1.88 μg/mL.The detection and the quantification limits were 0.047 μg/mL (19 μg/g) and 0.094 μg/mL (38 μg/g), respectively.The recoveries were (95.0±1.1)% and (99.4 ± 2.6)% for formaldehyde and glyoxal, respectively.This method has been fully validated to be applicable to quantitative analysis of trace amount of formaldehyde and glyoxal in varenicline tartrate API and its intermediate.Test results demonstrated that the contents of both formaldehyde and glyoxal met the permitted daily exposure (PDE) limits for the finished products of varenicline tartrate API as well as its intermediate, though the glyoxal contents in the crude intermediates were likely to exceed the limit.The established method is valuable for the manufacturing process and quality control of varenicline tartrate.
ABSTRACT
@#This study aimed to identify the related substances of lorazepam tablets by liquid chromatography mass spectrometry (LC-MS). To separate the related substances of lorazepam tablets, gradient elution was performed using acetonitrile and 0.1% acetic acid -20 mmol/L of ammonium acetate as mobile phase on Inert Sustain C18 (250 mm × 4.6 mm, 5 μm).The accurate mass and elemental composition of the parent ions and their product ions of related substances were determined by electrospray-ionization quadrupole time-of-flight high resolution mass spectrometry (ESI-Q-TOF/MS).The structures of the related substances were identified by spectral analysis. Under the established analytical condition, lorazepam and its related substances were adequately separated, and 22 major related substances with content greater than 0.1% were detected and identified by hyphenated techniques in lorazepam tablets and their stressed samples.Among them, 5 were the impurities listed in the USP or EP, and the others were unknown related substances identified for the first time in this paper.The LC-MS technique can effectively separate and identify the related substances of lorazepam tablets, which provides some reference for quality control.