The relationship between the drug concentration profiles in plasma and the drug doses in the colon
| Autor: | Hiroaki Nakagami, Shuichi Yada, Taro Kanamaru, Tsutomu Konno, Yasue Hosoi, Kazuhiro Yoshida, Shinichiro Tajiri |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Drug
Quinuclidines Diclofenac Colon media_common.quotation_subject Administration Oral Biological Availability Thiophenes Pharmacology Muscarinic Agonists Dosage form Diltiazem Dogs Oral administration Drug Discovery Anti-Allergic Agents medicine Ascending colon Animals Hypoglycemic Agents Antihypertensive Agents media_common Fexofenadine Dose-Response Relationship Drug Chemistry Anti-Inflammatory Agents Non-Steroidal General Chemistry General Medicine digestive system diseases Metformin Bioavailability Verapamil Area Under Curve Delayed-Action Preparations Terfenadine Anti-Arrhythmia Agents medicine.drug |
| Zdroj: | Chemicalpharmaceutical bulletin. 58(10) |
| ISSN: | 1347-5223 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|