著者

Hidetomo Yokoo Eiichi Yamamoto Sayaka Masada Nahoko Uchiyama Genichiro Tsuji Takashi Hakamatsuka Yosuke Demizu Ken-ichi Izutsu 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.9, pp.872-876, 2021-09-01 (Released:2021-09-01)

参考文献数

23

被引用文献数

13

---

N-Nitrosodimethylamine (NDMA) is a probable human carcinogen. This study investigated the root cause of the presence of NDMA in ranitidine hydrochloride. Forced thermal degradation studies of ranitidine hydrochloride and its inherent impurities (Imps. A, B, C, D, E, F, G, H, I, J, and K) listed in the European and United States Pharmacopeias revealed that in addition to ranitidine, Imps. A, C, D, E, H, and I produce NDMA at different rates in a solid or an oily liquid state. The rate of NDMA formation from amorphous Imps. A, C, and E was 100 times higher than that from crystalline ranitidine hydrochloride under forced degradation at 110 °C for 1 h. Surprisingly, crystalline Imp. H, bearing neither the N,N-dialkyl-2-nitroethene-1,1-diamine moiety nor a dimethylamino group, also generated NDMA in the solid state, while Imp. I, as an oily liquid, favorably produced NDMA at moderate temperatures (e.g., 50 °C). Therefore, strict control of the aforementioned specific impurities in ranitidine hydrochloride during manufacturing and storage allows appropriate control of NDMA in ranitidine and its pharmaceutical products. Understanding the pathways of the stability related NDMA formation enables improved control of the pharmaceuticals to mitigate this risk.

著者

Hidetomo Yokoo Seiji Tanaka Eiichi Yamamoto Genichiro Tsuji Yosuke Demizu Nahoko Uchiyama

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.71, no.1, pp.58-63, 2023-01-01 (Released:2023-01-01)

参考文献数

33

被引用文献数

1

---

Understanding the characteristics of crystal polymorphism of active pharmaceutical ingredients and analyzing them with high sensitivity is important for quality of drug products, appropriate characterization strategies, and appropriate screening and selection processes. However, there are few methods to measure intra- and intermolecular correlations in crystals other than X-ray crystallography, for which it is sometimes difficult to obtain suitable single crystals. Recently, solid-state NMR has been recognized as a straightforward method for measuring molecular correlations. In this study, we selected ranitidine hydrochloride, which is known to exist in two forms, 1 and 2, as the model drug and investigated each form using solid-state NMR. In conducting the analysis, rotating the sample tube, which had a 1-mm inner diameter, increased the solid-state NMR resolution at 70 kHz. The 1H–14N dipolar-based heteronuclear multiple quantum coherence (D-HMQC) analysis revealed the intermolecular correlation of Form 1 between the N atom of the nitro group and a proton of the furan moiety, which were closer than those of the intramolecular correlation reported using single X-ray crystal analysis. Thus, 1H–14N D-HMQC analysis could be useful for characterizing intermolecular interaction in ranitidine hydrochloride crystals. In addition, we reassigned the 13C solid-state NMR signals of ranitidine hydrochloride according to the liquid-state and multiple solid-state NMR experiments.

著者

Makoto Oba Mika Shibuya Yuto Yamaberi Hidetomo Yokoo Satoshi Uchida Atsushi Ueda Masakazu Tanaka

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.71, no.3, pp.250-256, 2023-03-01 (Released:2023-03-01)

参考文献数

23

被引用文献数

3

---

Amphipathic peptides composed of cationic amino acids and hydrophobic amino acids have cell-penetrating ability and are often used as a delivery tool for membrane-impermeable compounds. Small interfering RNA (siRNAs) are one of the delivery targets for such cell-penetrating peptides (CPPs). Cationic CPPs can associate with anionic siRNAs by electrostatic interactions resulting in the formation of nano-sized complexes, which can deliver siRNAs intracellularly. CPPs containing unnatural amino acids offer promising tools to siRNA delivery. However, the detailed structure–activity relationship in siRNA delivery has been rarely studied. In the current study, we designed peptides containing dipropylglycine (Dpg) and explored the cellular uptake and cytotoxicity of peptide/siRNA complexes. The amphipathic structure of the peptides played a key role in complexation with siRNAs and intracellular siRNA delivery. In the amphipathic peptides, cellular uptake of siRNA increased with increasing peptide length, but cytotoxicity was reduced. A peptide containing four Dpg exhibited an effective gene-silencing effect with small amounts of peptides without cytotoxicity in medium containing serum. These findings will be helpful for the design of novel CPPs for siRNA delivery.

著者

Yasuhiro Abe Eiichi Yamamoto Hiroyuki Yoshida Akiko Usui Naomi Tomita Hitomi Kanno Sayaka Masada Hidetomo Yokoo Genichiro Tsuji Nahoko Uchiyama Takashi Hakamatsuka Yosuke Demizu Ken-ichi Izutsu Yukihiro Goda Haruhiro Okuda

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

pp.c20-00431, (Released:2020-08-08)

参考文献数

28

被引用文献数

20

---

The purpose of this study was to elucidate the effect of high-temperature storage on the stability of ranitidine, specifically with respect to the potential formation of N-nitrosodimethylamine (NDMA), which is classified as a probable human carcinogen. Commercially available ranitidine reagent powders and formulations were stored under various conditions, and subjected to LC-MS/MS analysis. When ranitidine tablets from two different brands (designated as tablet A and tablet B) were stored under accelerated condition (40°C with 75% relative humidity), following the drug stability guidelines issued by the International Conference on Harmonisation (ICH-Q1A), for up to 8 weeks, the amount of NDMA in them substantially increased from 0.19 to 116 ppm and from 2.89 to 18 ppm, respectively. The formation of NDMA that exceeded the acceptable daily intake limit (0.32 ppm) at the temperature used under accelerated storage conditions clearly highlights the risk of NDMA formation in ranitidine formulations when extrapolated to storage under ambient conditions. A forced-degradation study under the stress condition (60°C for 1 week) strongly suggested that environmental factors such as moisture and oxygen are involved in the formation of NDMA in ranitidine formulations. Storage of ranitidine tablets and reagent powders at the high temperatures also increased the amount of nitrite, which is considered one of the factors influencing NDMA formation. These data indicate the necessity of controlling/monitoring stability-related factors, in addition to controlling impurities during the manufacturing process, in order to mitigate nitrosamine-related health risks of certain pharmaceuticals.