1.Identification of amino alcohols related substances of atenolol by LC-Q-TOF/MS
Wenzhu QI ; ZOU ZOU ; Yitong GUAN ; Min SONG ; Taijun HANG
Journal of China Pharmaceutical University 2020;51(5):544-555
To identify the amino alcohols related substances in atenolol. The related substances in atenolol and its stressed samples were pre-column derivatized with 9-fluorenylmethyl chloroformate. The separation was carried out on an Inertsil ODS-SP column (250 mm×4.6 mm, 5 μm) with linear gradient elution by methanol-ammonium acetate solution as the mobile phases. Electrospray positive ionization high-resolution Q-TOF/MS was used for the determination of the accurate masses and elemental compositions of the parent and fragment ions of these related substance derivatives. The structures of all the detected substances were identified by spectral analysis and synthetic analysis. Under the established conditions, atenolol and its amino alcohols related substances were well separated, and a total of 14 impurity peaks were detected and identified, of which 12 were related substances and 2 were derivatization reaction by-products. The established LC-MS method provides a reference for the examination and quality control of atenolol related substances.
2.Determination of formaldehyde and glyoxal in varenicline tartrate using derivative method with HPLC
Yitong GUAN ; Pengwei HU ; Wenyu ZOU ; Yuting LU ; Min SONG ; Taijun HANG
Journal of China Pharmaceutical University 2021;52(3):332-338
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.
3.Management of hypoparathyroidism during pregnancy
Chinese Journal of Endocrinology and Metabolism 2019;35(2):153-156
Hypoparathyroidism during pregnancy is an uncommon clinical problem, By presenting a case of post-surgical hypoparathyroidism during pregnancy, this paper reviewed calcium physiology in pregnancy, as well as characteristics of pregnant women with hypoparathyroidism which differ from those of normal pregnant women in order to help readers better undarstand the complexity of this problem and management of hypoparathyroidism during pregnancy.
4.Progress of hereditary thrombocytopenia in children
Yitong GUAN ; Rui ZHANG ; Runhui WU ; Tianyou WANG
International Journal of Pediatrics 2022;49(9):577-581
Hereditary thrombocytopenia(HT)is a hemorrhagic disease characterized by thrombocytopenia caused by genetic variation.HT can be manifested as simple thrombocytopenia or combined syndrome, and its clinical manifestations are complex.It often occurs in children.The unique clinical characteristics of HT are platelet dysfunction, unstable course of the disease and susceptibility to other diseases.Due to different pathogenic genes, the treatment and prognosis of HT are diverse.The evaluation of hemorrhage in the clinical management of HT children is very important.In addition, platelet transfusion, thrombopoietin receptor agonists, hematopoietic stem cell transplantation and gene therapy also supply new ideas for HT treatment.This review summarized the current research progress on HT, in order to help clinicians comprehensively identify HT and take active and effective treatment programs.