Multi-Gram Scale Synthesis and Characterization of Mometasone Furoate EP Impurity C.

Mometasone furoate is a synthetic corticosteroid used in the treatment of skin inflammatory conditions, hay fever and asthma. The industrial manufacturing routes to mometasone furoate are generally accompanied by the formation of numerous process impurities that need to be detected and quantified, as requested by regulatory authorities. The ready availability of such impurities in the required quantity and purity is therefore essential for toxicological studies, analytical method development and process validation. Herein, we report the multi-gram scale preparation of 21'-chloro-(16'α-methyl-3',11',20'-trioxo-pregna-1',4'-dien-17'-yl)-furan-2-carboxylate (mometasone furoate EP impurity C), one of the known impurities of mometasone furoate. This study also includes the systematic investigation of the final acylation step, as well as the characterization of the difuroate enol ether intermediate and its conversion to the target impurity C.

Screening potential anaphylactoid components in vinpocetine injection using a high expression Mas-related G-protein-coupled receptor X2 cell membrane chromatography.

Vinpocetine injection is often used in clinical treatment of acute cardiovascular and cerebrovascular diseases. However, it was reported that vinpocetine injection caused allergic reactions in clinical use; therefore, its safety needs urgent attention. Until now, research on its sensitization is rarely reported. Here, the components contained in three vinpocetine injections were examined. It was found that besides vinpocetine, the synthetic raw material vincamine, the excipients benzyl alcohol and ethyl p-toluenesulfonate, and the impurities A, B, C, and D, which are excipients specified in the European Pharmacopoeia, were also present in them. Then the Mas-related G-protein-coupled receptor X2 (MRGPRX2)-HEK293 cell membrane chromatography was used to investigate the affinity of them with MRGPRX2 and found that vinpocetine, vincamine, and impurities A, B, C, and D bind to MRGPRX2. Afterwards, these compounds were further used to investigate the local sensitization ability in vivo. The results showed that vinpocetine, vincamine, and impurity C could induce swelling of the paw and decrease body temperature in mice, but only impurity C could cause local skin mast cell degranulation and serum histamine release increase. In vitro, the results also indicated that impurity C could increase intracellular [Ca2+ ] in MRGPRX2-HEK293 cells, whereas vinpocetine and vincamine did not. Therefore, the impurity C was the potential anaphylactoid component in vinpocetine injection, which may be one of the reasons for the occurrence of allergic reactions in the clinical use of vinpocetine injection. This work provides evidence on the sensitization of impurity C and also contributes to promoting the clinical safety of vinpocetine injection.

Preparation process and structure confirmation of impurity C of rupatifen fumarate / 中国药科大学学报

@#The high-purity impurity C was isolated and purified from a new anti-allergic drug, rupatifen, by nucleophilic substitution reaction with bromobutaric acid, and its structure was confirmed by IR, UV, MS, 1H NMR, 13C NMR, DEPT135°,HSQC, HMBC, and 1H-1HCOSY. The preparation process of impurity C in this study was simple and easy to obtain under mild conditions, with the purity of 99.0% and the yield of 25%-30%;and the sample met the target compound by structural confirmation. The preparation process and structure confirmation provided sufficient impurity C reference substance for impurity research of raw materials and preparations of rupatifen fumarate, which laid a solid foundation for quality research of new drugs.

Preparation of impurity C of doxycycline hyclate and its evaluation of in vitro antimicrobial activity and toxicity / 中国药科大学学报

@#This study aimed to isolate and prepare highly purified impurity C from doxycycline hyclate by a preparative HPLC method and to inspect the toxicity and in vitro antimicrobial activity of the impurity C of doxycycline hyclate. The solution of doxycycline hyclate treated with heat produced a solution containing 10% of impurity C which was firstly separated by the Sapphire C18(21. 2 mm×250 mm, 5 μm)column with 0. 1% acetic acid-acetonitrile(83 ∶17)as the mobile phase at 20 mL/min. Secondly, rotary evaporation of the eluted solution at the time of 8. 4 min was performed at 50 °C to remove organic solvent. Then the target product was prepared after freeze drying of evaporated solution adjusting pH to 1. 8 with formic acid. The target product was identified with ultraviolet absorbance(UV), infrared(IR), mass spectrometry(MS)and nuclear magnetic resonance(NMR), and its purity was be determined by HPLC. Meanwhile, cytotoxicity and genotoxicity in the Chinese hamster lung cells, toxicity on the development of zebrafish embryos and in vitro antimicrobial activity were compared among impurity C of doxycycline hyclate, doxycycline, metacycline and β-doxycycline. Results showed that prepared product was confirmed to be the impurity C of doxycycline hyclate. Its purity was 90. 1%, which had been the highest so far. In the cellular toxic tests and genetic toxic tests of Chinese hamster lung cells, impurity C of doxycycline hyclate, doxycycline, metacycline and β-doxycycline were somewhat toxic to Chinese hamster lung cells. Toxicity gradually decreased from doxycycline, impurity C of doxycycline hyclate, β-doxycycline to metacycline from -S9mix test results; toxicity gradually decreased from doxycycline, β-doxycycline, impurity C of doxycycline hyclate to metacycline from +S9mix test results; the aberration rate of all the tested related substances was less than 5%, and no obvious genotoxicity was found. According to test results of the development of zebrafish embryos, impurity C of doxycycline hyclate showed the strongest teratogenicity and lethality. Invitro antimicrobial tests revealed that impurity C of doxycycline hyclate had a weaker antimicrobial activity, and invitro antimicrobial activity potential of the tested compounds followed the order: metacycline, doxycycline, impurity C of doxycycline hyclate, β-doxycycline. Studies on safety and effectiveness indicated that impurity C of doxycycline hyclate belonged to toxic and ineffective impurity and need to be controlled individually in quality standard. A useful suggestion was given to revise the quality standard of doxycycline hyclate and its preparation in the current Pharmacopoeia of the People′s Republic of China.

Preparation of impurity C in benzathine benzylpenicillin products / 中国药学杂志

OBJECTIVE: To prepare impurity C in benzathine benzylpenicillin products. METHODS: Using the mother liquor of benzathine benzylpenicillin, impurity C was prepared by means of vacuum distillation, column chromatography, and recrystallization. Its molecular structure was confirmed with UV, IR, MS, NMR and elemental analysis. Its purity and correction factor were determined by HPLC method. The contents of impurity C in the samples were determined by external standard method. RESULTS: The prepared product was proved to be impurity C by structure confirmation. CONCLUSION: The preparation of impurity C in benzathine benzylpenicillin products has important significance for the control of related substances of benzathine benzylpenicillin products.