著者

Nahoko Uchiyama Junko Hosoe Naoki Sugimoto Kyoko Ishizuki Tatsuo Koide Mika Murabayashi Naoto Miyashita Kengo Kobayashi Yoshinori Fujimine Toshiyuki Yokose Katsuya Ofuji Hitoshi Shimizu Takashi Hasebe Yumi Asai Eri Ena Junko Kikuchi Kohei Kiyota Kazuhiro Fujita Yoshinobu Makino Naoko Yasobu Yoshiaki Iwamoto Toru Miura Koji Mizui Katsuo Asakura Takako Suematsu Hitomi Muto Ai Kohama Takashi Goto Masu Yasuda Tomohiko Ueda Yukihiro Goda

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.69, no.7, pp.630-638, 2021-07-01 (Released:2021-07-01)

参考文献数

22

被引用文献数

5

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Recently, quantitative NMR (qNMR), especially 1H-qNMR, has been widely used to determine the absolute quantitative value of organic molecules. We previously reported an optimal and reproducible sample preparation method for 1H-qNMR. In the present study, we focused on a 31P-qNMR absolute determination method. An organophosphorus compound, cyclophosphamide hydrate (CP), listed in the Japanese Pharmacopeia 17th edition was selected as the target compound, and the 31P-qNMR and 1H-qNMR results were compared under three conditions with potassium dihydrogen phosphate (KH2PO4) or O-phosphorylethanolamine (PEA) as the reference standard for 31P-qNMR and sodium 4,4-dimethyl-4-silapentanesulfonate-d6 (DSS-d6) as the standard for 1H-qNMR. Condition 1: separate sample containing CP and KH2PO4 for 31P-qNMR or CP and DSS-d6 for 1H-qNMR. Condition 2: mixed sample containing CP, DSS-d6, and KH2PO4. Condition 3: mixed sample containing CP, DSS-d6, and PEA. As conditions 1 and 3 provided good results, validation studies at multiple laboratories were further conducted. The purities of CP determined under condition 1 by 1H-qNMR at 11 laboratories and 31P-qNMR at 10 laboratories were 99.76 ± 0.43 and 99.75 ± 0.53%, respectively, and those determined under condition 3 at five laboratories were 99.66 ± 0.08 and 99.61 ± 0.53%, respectively. These data suggested that the CP purities determined by 31P-qNMR are in good agreement with those determined by the established 1H-qNMR method. Since the 31P-qNMR signals are less complicated than the 1H-qNMR signals, 31P-qNMR would be useful for the absolute quantification of compounds that do not have a simple and separate 1H-qNMR signal, such as a singlet or doublet, although further investigation with other compounds is needed.

著者

Nahoko Uchiyama Junko Hosoe Naoki Sugimoto Kyoko Ishizuki Tatsuo Koide Mika Murabayashi Naoto Miyashita Kengo Kobayashi Yoshinori Fujimine Toshiyuki Yokose Katsuya Ofuji Hitoshi Shimizu Takashi Hasebe Yumi Asai Eri Ena Junko Kikuchi Kohei Kiyota Kazuhiro Fujita Yoshinobu Makino Naoko Yasobu Yuko Yamada Yoshiaki Iwamoto Toru Miura Koji Mizui Katsuo Asakura Takako Suematsu Ai Kohama Yukihiro Goda

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.69, no.1, pp.118-123, 2021-01-01 (Released:2021-01-01)

参考文献数

11

被引用文献数

10

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Quantitative NMR (qNMR) is applied to determine the absolute quantitative value of analytical standards for HPLC-based quantification. We have previously reported the optimal and reproducible sample preparation method for qNMR of hygroscopic reagents, such as saikosaponin a, which is used as an analytical standard in the assay of crude drug section of Japanese Pharmacopoeia (JP). In this study, we examined the absolute purity determination of a hygroscopic substance, indocyanine green (ICG), listed in the Japanese Pharmaceutical Codex 2002, using qNMR for standardization by focusing on the adaptation of ICG to JP. The purity of ICG, as an official non-Pharmacopoeial reference standard (non-PRS), had high variation (86.12 ± 2.70%) when preparing qNMR samples under non-controlled humidity (a conventional method). Additionally, residual ethanol (0.26 ± 0.11%) was observed in the non-PRS ICG. Next, the purity of non-PRS ICG was determined via qNMR when preparing samples under controlled humidity using a saturated sodium bromide solution. The purity was 84.19 ± 0.47% with a lower variation than that under non-controlled humidity. Moreover, ethanol signal almost disappeared. We estimated that residual ethanol in non-PRS ICG was replaced with water under controlled humidity. Subsequently, qNMR analysis was performed when preparing samples under controlled humidity in a constant temperature and humidity box. It showed excellent results with the lowest variation (82.26 ± 0.19%). As the use of a constant temperature and humidity box resulted in the lowest variability, it is recommended to use the control box if the reference ICG standard is needed for JP assays.

著者

Kotaro Imamura Yumi Asai Kazuhiro Watanabe Akizumi Tsutsumi Akihito Shimazu Akiomi Inoue Hisanori Hiro Yuko Odagiri Toru Yoshikawa Etsuko Yoshikawa Norito Kawakami

出版者

Japan Society for Occupational Health

雑誌

Journal of Occupational Health (ISSN:13419145)

巻号頁・発行日

vol.60, no.4, pp.298-306, 2018-07-20 (Released:2018-07-25)

参考文献数

29

被引用文献数

16

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Objectives: This retrospective cohort study evaluated the impact of the Stress Check Program, a recently introduced national policy and program aimed at reducing psychological distress among Japanese workers. Methods: A baseline survey was conducted from November 2015 to February 2016, the period when Japan began enforcing the Stress Check Program. A one-year follow-up survey was conducted in December 2016. In the follow-up survey, two exposure variables were collected: having taken the annual stress survey, and experiencing an improvement in the psychosocial work environment. Psychological distress was assessed using the Brief Job Stress Questionnaire (BJSQ) at baseline and 1-year follow-up. The two exposure variables were used to define four groups: "Neither", "Stress survey (SS) only", "Psychosocial work environment improvement (WI) only", and "Both". BJSQ results were analyzed using repeated measures general linear modeling (GLM). Results: The study included 2,492 participants: 1,342 in the "Neither" group, 1,009 in the "SS only" group, 76 in the "WI only" group, and 65 in the "Both" group. Overall time-group interaction effects were not significant. The "Both" group showed significantly greater improvements in psychological distress than the "Neither" group (p = 0.02) at the 1-year follow-up, although the effect size was small (d = -0.14). Conclusions: Combination of the annual stress survey and improvement in psychosocial work environment may have been effective in reducing psychological distress in workers, although the effect size was small.