Intestinal absorption mechanism of tebipenem pivoxil, a novel oral carbapenem: involvement of human OATP family in apical membrane transport.

Tebipenem pivoxil (TBPM-PI) is an oral carbapenem antibiotic for treating otolaryngologic and respiratory infections in pediatric patients. This agent is a prodrug to improve intestinal absorption of TBPM, an active form, and an absorption rate of TBPM-PI is higher than those of other prodrug-type β-lactam antibiotics. In the present study, we hypothesized that a certain mechanism other than simple diffusion is involved in the process of improved intestinal absorption of TBPM-PI and examined the mechanism.

Active uptake of ulifloxacin from plasma to lung that controls its concentration in epithelial lining fluid.

Ulifloxacin is a new quinolone antibiotic and it is effective against pneumonia. We previously showed that it is highly distributed into the epithelial lining fluid (ELF) in rats, which might be resulting from certain active transport. The transport system has not been, however, clarified yet.

Proposal of membrane transport mechanism of protein-unbound ulifloxacin into epithelial lining fluid determined by improved microdialysis.

Microdialysis method (MD) is useful for sampling protein-unbound substances in vivo. Generally in the MD, a reference compound is used to correct differences in drug permeation clearance through a dialysis membrane in vivo and in vitro. No reference compound was, however, used for determination of a protein-unbound drug concentration in the epithelial lining fluid (ELF).

Transporter-mediated hepatic uptake of ulifloxacin, an active metabolite of a prodrug-type new quinolone antibiotic prulifloxacin, in rats.

Prulifloxacin (PUFX) is a prodrug-type new quinolone antibiotic and immediately converted to an active metabolite, ulifloxacin (UFX). It has been previously reported that UFX is highly excreted into the bile, although the hepatic uptake process of UFX has not been investigated yet. In this study, we attempted to characterize the mechanism of hepatic uptake of UFX in rats.

Tricyclic pharmacophore-based molecules as novel integrin alpha(v)beta3 antagonists. Part 2: synthesis of potent alpha(v)beta3/alpha(IIb)beta3 dual antagonists.

We synthesized 4-aminopiperidine derivatives of our prototype integrin alpha(v)beta3 antagonist 1 in an attempt to increase the activity and water solubility. Introduction of one or two hydrophilic moieties into the central aromatic ring and/or the benzene ring at the C-terminus of 1 increased water solubility and enhanced inhibition of cell adhesion. The results of a structure-activity relationships (SAR) study indicated that the torsion angle between the central aromatic ring and the piperidine ring, and the acidity at the sulfonamide moiety, might be important for alpha(v)beta3 receptor binding activity.