Membrane-solvent-solute interaction in a model permeation system

Area of Science:

• Materials Science
• Chemical Engineering
• Pharmacokinetics

Background:

• Parabens are widely used preservatives.
• Understanding paraben transport through polymer membranes is crucial for product formulation and safety.
• Polydimethylsiloxane (PDMS) is a common polymer used in various applications.

Purpose of the Study:

• To investigate the influence of alcohol solvents on methyl- and propylparaben flux through PDMS membranes.
• To elucidate the mechanisms governing paraben transport in the presence of alcohol vehicles.
• To assess the impact of alcohol-membrane and alcohol-paraben interactions on flux.

Main Methods:

• Investigated paraben flux using various alcohol donors and PDMS membranes.
• Measured alcohol uptake by neat PDMS to correlate with solvent-membrane interaction.
• Analyzed the relationship between paraben solubility, diffusion, and flux in different solvent systems.

Main Results:

• Saturated alcohol vehicles significantly increased paraben flux compared to water and glycol systems.
• Alcohol uptake correlated with paraben flux, indicating solvent-membrane interaction is key.
• Alcohols primarily increased paraben membrane solubility, with a minor effect on diffusion coefficient.
• High paraben solubility in alcohol donors led to reduced solvent-membrane interaction and attenuated flux.

Conclusions:

• Alcohol solvents enhance paraben flux through PDMS membranes mainly by increasing paraben solubility.
• The observed changes in membrane barrier properties are dependent on sorbed alcohol and are reversible.
• Findings provide insights into paraben migration and partitioning in formulations containing alcohol-based vehicles.