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Generation and Control of Electrohydrodynamic Flows in Aqueous Electrolyte Solutions
Published on: September 7, 2018
Electroosmotic flow and its contribution to iontophoretic delivery
Natalie R Herr1, Brian M Kile, Regina M Carelli
1Department of Chemistry and Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA.
Analytical Chemistry
|October 25, 2008
Summary
Quantitative iontophoresis is now possible. Researchers found that electroosmotic flow (EOF) drives molecule ejection, and capillary electrophoresis can predict its percentage for accurate drug delivery.
Area of Science:
- Electrochemistry
- Analytical Chemistry
- Biomedical Engineering
Background:
- Iontophoresis facilitates charged molecule movement via electric current.
- Traditional iontophoresis lacks quantitative accuracy.
- Carbon-fiber electrodes were integrated with iontophoretic barrels to enhance characterization.
Purpose of the Study:
- To characterize the ejection of charged and neutral species using novel electrode configurations.
- To determine the contributions of iontophoretic and electroosmotic forces to molecule ejection.
- To develop a method for quantitative iontophoresis.
Main Methods:
- Utilized carbon-fiber electrodes with iontophoretic barrels.
- Employed the neutral electroactive molecule 2-(4-nitrophenoxy) ethanol (NPE) as a marker for electroosmotic flow (EOF).
- Applied capillary electrophoresis (CE) to analyze charged and neutral compounds alongside the EOF marker.
Main Results:
- Ejection is driven by a combination of iontophoretic and electroosmotic forces.
- A positive correlation exists between ejected volume and barrel tip diameter for neutral species.
- The percentage of ejection due to EOF is constant when paired with an EOF marker and correlates with electrophoretic mobility differences.
Conclusions:
- Capillary electrophoresis can accurately predict the percentage of ejection attributable to EOF.
- Quantitative iontophoresis is achievable, particularly for electrochemically inactive drugs, by using NPE as an EOF marker.
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