著者

袴塚 高志 鎌倉 浩之 渡辺 淳子 香取 征典 松本 和弘 石丸 順之 諸田 隆 合田 幸広

出版者

一般社団法人 日本生薬学会

雑誌

生薬学雑誌 (ISSN:13499114)

巻号頁・発行日

vol.74, no.2, pp.89-97, 2020-08-20 (Released:2021-09-08)

参考文献数

7

---

Dry extract preparations of Kampo medicines for prescription were approved for use approximately 40 years ago in Japan. Presently, most Kampo medicines are prepared in the form of granules with a few being prepared as tablets or capsules. Granule formulations are generally unsuitable for the elderly due to their bulky nature. Although patients and Kampo manufacturers have expressed a need for the introduction of more acceptable granule alternatives, their introduction has been a challenge due to the lack of guidelines based on bioequivalence evaluations for medicines that include multiple chemical components. For resolving this issue, the researchers at the National Institute of Health Sciences initiated a study in 2009 funded by the Ministry of Health, Labour and Welfare. Several ingredients in Kampo extract products and corresponding standard decoctions were detectable and measurable in human plasma, and some compounds have been reported to be promising candidates for application in bioequivalence evaluations of Kampo formulations. The purpose of the present study was to investigate the potential to assess bioequivalence between kakkonto extract granules and tablets on the basis of the “Guidelines for Bioequivalence Testing of Generic Drugs (partial revision, PFSB/ELD Notification No. 0229010 dated February 29, 2012).”We investigated the pharmacokinetics of ephedrine and pseudoephedrine, which are ingredients derived from Ephedra Herba in kakkonto formulations, following the oral administration of kakkonto extract granules (one pack) and kakkonto extract tablets (eight tablets). The study was conducted as a two-group, two-period, and open-label crossover study in healthy Japanese volunteers. The plasma concentrations of ephedrine and pseudoephedrine following the administration of the drugs were measured using liquid chromatography with tandem mass spectrometry. Subsequently, we calculated their pharmacokinetic parameters and evaluated their bioequivalence. Analysis of variance using the area under the plasma concentration time curve (AUC) and the maximum plasma concentration (Cmax) of both ingredients revealed that while AUC indicated bioequivalence, Cmax values were significantly different. Plasma concentration levels in both formulations were similar in most volunteers and differed among some volunteers, which was attributed to a high number of tablets per dose as opposed to intra-individual variation. We concluded that ephedrine and pseudoephedrine in kakkonto extracts are good marker compounds for the evaluation of bioequivalence in different forms of kakkonto products. Our results suggest that the marker compounds exhibiting similarity in pharmacokinetic parameters following the administration of Kampo extract granules and the corresponding standard decoction could be applied as markers for the evaluation of bioequivalence between already-approved Kampo extract granules and novel Kampo products based on the same extract as that of granules.