著者

Nasa Sakamoto Naoya Tsuno Ryotaro Koyama Katsuhiko Gato Varin Titapiwatanakun Kazuhiko Takatori Toshiro Fukami

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.10, pp.995-1004, 2021-10-01 (Released:2021-10-01)

参考文献数

51

被引用文献数

4

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Cocrystal engineering can alter the physicochemical properties of a drug and generate a superior drug candidate for formulation design. Oxyresveratrol (ORV) exhibits a poor solubility in aqueous environments, thereby resulting in a poor bioavailability. Extensive cocrystal screening of ORV with 67 cocrystal formers (coformers) bearing various functional groups was therefore conducted using grinding, liquid-assisted grinding, solvent evaporation, and slurry methods. Six cocrystals (ORV with betaine (BTN), L-proline (PRL), isonicotinamide, nicotinamide, urea, and ethyl maltol) were found, including four novel cocrystals. Powder X-ray diffraction, low frequency Raman spectroscopy, and thermal analysis revealed unique crystal forms in all obtained samples. Conventional Raman and infrared data differentiated the cocrystals by the presence or absence of a hydrogen bond interacting with the aromatic ring of ORV. The crystal structures were then elucidated by single-crystal X-ray diffraction. Two new cocrystals consisting of ORV : BTN (2 : 3) and ORV : PRL : H2O (1 : 2 : 1) were identified, and their crystal structures were solved. We report novel cocrystalline solids of ORV with improved aqueous solubilities and the unique cage-like crystal structures.

著者

Takuya Hoshino Motoshige Azuma Yuki Yamada Varin Titapiwatanakun Mika Yoshimura Fujii Yoshihisa Yamamoto Tatsuo Koide Toshiro Fukami

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.67, no.9, pp.929-934, 2019-09-01 (Released:2019-09-01)

参考文献数

25

被引用文献数

3

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We investigated the water contents in commercial semi-solid preparations used for pressure ulcer (PU) treatment using near-IR spectroscopy (NIRS) and compared the results with those measured using the Karl Fischer (KF) method. The aim of this study was to determine a standard method and select the appropriate topical preparation with the optimal moisture for PU treatment. The water absorption properties of bases and formulations were evaluated with a time-dependent factor using Transwell as the model membrane. KF and NIRS were applicable as measurement methods of the water content in semi-solid formulations. NIRS was shown to be a useful, simple, nondestructive tool that is more advantageous than the KF method. The water absorption characteristics tested using Transwell revealed that the rate of and capacity for water absorption are determined not only by the absorption ability of the polymer base but also by other factors, such as the osmotic pressure exerted by additives. KF and NIR measurements can be used to choose external skin preparations to control the amount of water in PU treatment.