著者

Keiko Unno Hiroshi Yamada Kazuaki Iguchi Hitoshi Ishida Yasunori Iwao Akio Morita Yoriyuki Nakamura

出版者

公益社団法人日本薬学会

雑誌

Biological and Pharmaceutical Bulletin (ISSN:09186158)

巻号頁・発行日

vol.40, no.6, pp.902-909, 2017-06-01 (Released:2017-06-01)

参考文献数

38

被引用文献数

19

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Theanine, an amino acid in tea, has significant anti-stress effects on animals and humans. However, the effect of theanine was blocked by caffeine and gallate-type catechins, which are the main components in tea. We examined the anti-stress effect of green tea with lowered caffeine, low-caffeine green tea, on humans. The study design was a single-blind group comparison and participants (n=20) were randomly assigned to low-caffeine or placebo tea groups. These teas (≥500 mL/d), which were eluted with room temperature water, were taken from 1 week prior to pharmacy practice and continued for 10 d in the practice period. The participants ingested theanine (ca. 15 mg/d) in low-caffeine green tea. To assess the anxiety of participants, the state-trait anxiety inventory test was used before pharmacy practice. The subjective stress of students was significantly lower in the low-caffeine-group than in the placebo-group during pharmacy practice. The level of salivary α-amylase activity, a stress marker, increased significantly after daily pharmacy practice in the placebo-group but not in the low-caffeine-group. These results suggested that the ingestion of low-caffeine green tea suppressed the excessive stress response of students. This study was registered at the University Hospital Medical Information Network (ID No. UMIN14942).

著者

Tomoko Otsuka Yosuke Kuroiwa Kazunari Sato Kazunari Yamashita Tadashi Hakomori Shin-ichiro Kimura Yasunori Iwao Shigeru Itai

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.66, no.5, pp.554-561, 2018-05-01 (Released:2018-05-01)

参考文献数

24

被引用文献数

6

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The properties of wet mass, which indicate the progress of high shear granulation processes, usually have an effect on final product properties, such as tablet dissolution. The mixer torque rheometer (MTR) is a useful tool for quantitatively measuring the ‘kneading state’ of wet mass and detecting differences in granules. However, there have been no studies of the relationship between the MTR torque and the final product properties to date. In this study, we measured the MTR torque of wet granules at different kneading states, which were prepared by changing the granulation conditions. We then evaluated the relationship between the MTR torque and the dissolution rate of the final product properties. The amperage of the high shear granulator is usually monitored during granulation, but we could not detect a difference in the kneading state through the amperage. However, using MTR torque we were able to quantify the difference of the wet mass. Moreover, MTR torque showed a high correlation with dissolution, compared with the correlations with other intermediate properties, such as granules particle size and tablet hardness. These other properties are affected by following processes and are not properties that directly relate to the kneading state. Thus, MTR torque is a property of wet mass after granulation, and it can be used to directly evaluate differences of the kneading state, and as a result, dissolution. These results indicate the importance of controlling the kneading state, i.e., the progress of granulation, and the utility of MTR for detecting differences in wet mass.