The Relationship between the Drug Concentration Profiles in Plasma and the Drug Doses in the Colon

Tajiri Shinichiro, Kanamaru Taro, Yoshida Kazuhiro, Hosoi Yasue, Konno Tsutomu, Yada Shuichi, Nakagami Hiroaki

doi:10.1248/cpb.58.1295

After the dosing of an extended-release (ER) formulation, compounds may exist in solutions at various concentrations in the colon because the drugs are released at various speeds from the ER dosage form. The aim of this study was to investigate the relationship between the drug concentration profiles in plasma and the drug doses in the colon. Several drug solutions of different concentrations were directly administered into the ascending colon of dogs using a lubricated endoscope, and the effects of the drug dose on colonic absorption were estimated. As a result, dose-dependency of colonic absorption varied from compound to compound. Although the relative bioavailability of colonic administration of diclofenac, metformin and cevimeline compared to oral administration was similar regardless of the drug doses in the colon, colonic absorption of diltiazem varied according to the doses. From the results of the co-administration of verapamil and fexofenadine, it was clear that diltiazem underwent extensive hepatic and gastrointestinal first-pass metabolism, resulting in a low area under the curves (AUC) at a low drug dose. During the design of oral ER delivery systems, a colonic absorption study of candidate compounds should be carried out at several solutions of different drug concentrations and assessed carefully.

The Relationship between the Drug Concentration Profiles in Plasma and the Drug Doses in the Colon

この論文をさがす

抄録

収録刊行物

参考文献 (37)*注記

キーワード

詳細情報詳細情報について

書き出し

問題の指摘

The Relationship between the Drug Concentration Profiles in Plasma and the Drug Doses in the Colon

この論文をさがす

抄録

収録刊行物

参考文献 (37)*注記

キーワード

詳細情報 詳細情報について

書き出し

問題の指摘

参加プロジェクトリスト

詳細情報詳細情報について