Related Experiment Video
Updated: Jun 10, 2026
08:23
Visualization of Bacterial Resistance using Fluorescent Antibiotic Probes
Published on: March 2, 2020
Metal cation-fluoroquinolone complexes do not permeate through the intestinal absorption barrier
Zakelj Simon1, Berginc Katja, Ursic Darko
1Faculty of Pharmacy, University of Ljubljana, Askerceva 7, 1000 Ljubljana, Slovenia. simon.zakelj@ffa.uni-lj.si
Journal of Pharmaceutical and Biomedical Analysis
|July 21, 2010
Summary
Metal cations significantly reduce fluoroquinolone absorption in the intestine by forming complexes. The ciprofloxacin-aluminum complex, specifically, cannot cross the intestinal barrier, impacting drug efficacy.
Area of Science:
- Pharmacology
- Drug Interactions
- Gastrointestinal Physiology
Background:
- A known interaction exists between fluoroquinolone antimicrobials and metal cations.
- The proposed mechanism involves reduced intestinal permeability due to complex formation, but in vitro studies yielded conflicting results.
- Previous in vitro studies used diluted solutions, not reflecting in vivo conditions.
Purpose of the Study:
- To investigate the interaction mechanism between fluoroquinolones and metal cations under more physiologically relevant conditions.
- To determine if the ciprofloxacin-aluminum complex can permeate the intestinal barrier.
Main Methods:
- Utilized rat intestine in side-by-side diffusion chambers.
- Employed saturated solutions of fluoroquinolones and metal cations in the donor compartment.
- Assessed the permeability of fluoroquinolone-metal cation complexes.
Main Results:
- Fluoroquinolone permeability was decreased in the presence of metal cations under saturated conditions.
- The ciprofloxacin-aluminum complex was found to be non-permeable across the intestinal mucosal membrane.
Conclusions:
- The in vivo interaction between fluoroquinolones and metal cations is sensitive to solution concentration and physiological conditions.
- Complex formation significantly hinders fluoroquinolone intestinal absorption, with the ciprofloxacin-aluminum complex being unable to cross the intestinal barrier.
Related Concept Videos
01:28Inhibitors of Bacterial DNA Synthesis
Bacterial pathogens depend on precise and efficient DNA replication to sustain infection. Two type II topoisomerases—DNA gyrase and topoisomerase IV—are critical to this process, as they resolve DNA supercoiling and unlink chromosomes during replication. Fluoroquinolones, synthetic derivatives of quinolones, exploit this mechanism by stabilizing the transient DNA–enzyme cleavage complex, preventing strand religation, and causing lethal double-strand breaks. These antibiotics are selectively...
01:17Pore Transport and Ion-Pair Transport
Pore transport and ion-pair formation are critical mechanisms for the absorption and distribution of drugs in the body.
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct microscopic...
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct microscopic...
01:20Factors Affecting Dissolution: Drug Permeability, Stability and Stereochemistry
Orally administered drugs primarily enter the systemic circulation via passive diffusion through the intestinal membranes. The drug's absorption is influenced by drug stability in the gastrointestinal GI tract, membrane permeability, the surface area available for absorption, luminal drug concentration, and residence time in the lumen. Drug permeability can be enhanced by adjusting the lipophilicity, polarity, or molecular size of the drug, promoting its passive transport across intestinal...
01:14Hepatic Drug Clearance: Role of Transporters
In the liver and bile canaliculi, influx and efflux transporters modification can influence intrinsic clearance. Transporters play a significant role in moving drugs within liver cells. Elaborate models, such as the Biopharmaceutical Classification System (BCS), are essential to relate transporters to drug disposition. This system categorizes drugs into four classes based on solubility and permeability, providing insights into elimination routes and the effects of transporters following oral...
01:19Drug Absorption: Factors Affecting GI Absorption
The process of oral drug absorption can be influenced by several factors. Weakly acidic drugs tend to be absorbed more readily from the stomach due to their nonionized state. However, absorption may be less efficient in the upper intestine, where drugs are often ionized. Interestingly, despite the stomach's apparent advantage for drug absorption, its mucous layer can hinder diffusion. Its surface area is also smaller than the intestine's, which can further slow down the absorption rate.
In...
In...
01:27Bioavailability Enhancement: Drug Permeability Enhancement
After oral administration, poor permeability often limits the rate at which drugs are absorbed through the intestinal epithelium. Enhancing drug permeability is crucial for effective therapy, and several strategies have been developed to overcome this challenge.One effective strategy involves the use of lipid-based formulations. These formulations enhance dissolution and solubility, targeting physiological mechanisms to increase drug absorption. This includes stimulating bile salt secretion,...