Sökning: "intestinal efflux"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden intestinal efflux.

1. 1. Drug Dissolution under Physiologically Relevant Conditions In Vitro and In Vivo

   Författare :Eva Persson; Hans Lennernäs; Bertil Abrahamsson; Peter Langguth; Uppsala universitet; []
   Nyckelord :Biopharmacy; solubility; drug dissolution; food effects; poorly soluble drugs; P-gp inhibition; drug absorption; pemeability; bile acids; phospholipids; human intestinal fluid; simulated intestinal fluid; neutral lipids; solid phase extraction; HPLC; Efflux; Biofarmaci;

   Sammanfattning : The general aim of the present project was to increase the understanding of the in vivo dissolution of poorly soluble drugs and thereby improve possibility to predict in vivo solubility from substance properties. Increased understanding of the in vivo limitations of drug solubility could potentially also generate ideas for improved formulation principles for poorly soluble compounds and more relevant in vitro dissolution test methods used in formulation development. LÄS MER

3. 2. Drug Transport and Metabolism in Rat and Human Intestine

   Författare :Sofia Berggren; Hans Lennernäs; Janet Hoogstraate; Patrick Augustijns; Uppsala universitet; []
   Nyckelord :Biopharmacy; Ussing chamber; microsome; single-pass perfusion; human; rat; intestine; permeability; efflux; P-glycoprotein; metabolism; cytochrome P450; ropivacaine; lidocaine; bupivacaine; Biofarmaci; PPX;

   Sammanfattning : One of the aims of this thesis was to investigate the involvement of efflux proteins, such as the P-glycoprotein (Pgp), in the drug transport in different regions of the rat and the human intestine. The intestinal extrusion of intracellularly formed CYP3A4 metabolites, including whether this extrusion might be mediated by Pgp, was also studied. LÄS MER

4. 3. Pulmonary Drug Absorption : In vitro and in vivo investigations of drug absorption across the lung barrier and its relation to drug physicochemical properties

   Författare :Ann Tronde; Gerrit Borchard; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pharmacy; lung; pulmonary; drug delivery; inhalation; drug transport; pharmacokinetics; absorption; bioavailability; drug metabolism; preclinical; rat; in vivo; isolated and perfused lung; Caco-2; nebulization catheter; aerosol; physicochemical; peptide; efflux; FARMACI; PHARMACY; FARMACI; Biopharmaceutics; biofarmaci;

   Sammanfattning : Although, pulmonary drug delivery is a well established means for targeting of drugs to the lungs for the treatment of respiratory diseases as well as for the systemic delivery of volatile anesthetic agents, drug absorption kinetics in the lung have not been subjected to extensive research. The main objective of this thesis was to investigate drug absorption characteristics of the lung barrier, using the isolated and perfused rat lung model and in vivo pharmacokinetic studies in rats. LÄS MER

5. 4. Intestinal Permeability and Presystemic Extraction of Fexofenadine and R/S-verapamil

   Författare :Christer Tannergren; Hans Lennernäs; Dirk KF Meijer; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Biopharmacy; Bioavailability; Fexofenadine; Verapamil; P-glycoprotein; CYP3A4; OATP; Enantioselective; Permeability; Caco-2; Intestinal perfusion; Biofarmaci; Biopharmacy; Biofarmaci;

   Sammanfattning : The main objective of this thesis was to investigate the in vivo relevance of membrane transporters and cytochrome P450 (CYP) 3A4-mediated metabolism in the intestine and liver for the bioavailability of drugs in humans after oral administration.In the first part of the thesis, the main transport mechanisms involved in the intestinal absorption and bioavailability were investigated for fexofenadine, a minimally metabolized drug, which is a substrate for P-glycoprotein (P-gp) and members of organic anion transporting polypeptide (OATP) family. LÄS MER

7. 5. Refined in vitro Models for Prediction of Intestinal Drug Transport : Role of pH and Extracellular Additives in the Caco-2 Cell Model

   Författare :Sibylle Neuhoff; Per Artursson; Anna-Lena Ungell; Patrick Augustijns; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pharmacy; Caco-2 cells; membrane permeability; drug permeation; drug efflux ratios; drug uptake ratios; Cremophor EL; bovine serum albumin; pH-dependent permeability; drug transport; FARMACI; PHARMACY; FARMACI;

   Sammanfattning : Drug transport across the intestinal epithelium is roughly predicted from permeability values obtained from Caco-2 cell monolayers. This thesis examines the important role of pH and extracellular additives for increasing the reliability and predictivity of the in vitro screening system, Caco-2. LÄS MER