Membrane properties for permeability testing: Skin versus synthetic membranes

Area of Science:

• Pharmacology
• Materials Science
• Biomedical Engineering

Background:

• Synthetic membranes like cellulose acetate (CA) are commonly used in diffusion studies for topical and transdermal formulations.
• Evaluating the permeability of these synthetic membranes against human skin is crucial for accurate formulation development.

Purpose of the Study:

• To compare the permeability of human skin with two synthetic membranes: cellulose acetate and Strat-M®.
• To assess the suitability of Strat-M® as a replacement for human skin in diffusion studies.

Main Methods:

• Permeation studies were conducted using lipophilic and hydrophilic compounds in various forms (solutions, formulated, marketed dosage forms).
• The permeability of cellulose acetate and Strat-M® membranes was compared against human skin.
• Variability in permeability values was analyzed for each membrane type.

Main Results:

• Strat-M® demonstrated higher permeability for hydrophilic compounds compared to lipophilic ones.
• Strat-M® exhibited less variability in permeability values than typically observed with biological membranes.
• The permeability of Strat-M® was found to be closer to human skin than that of cellulose acetate (CA > Strat-M® > Human skin).

Conclusions:

• Strat-M® is a more suitable substitute than cellulose acetate for diffusion tests in topical and transdermal formulation studies.
• Strat-M® offers a reliable alternative to human skin, with minimal lot-to-lot variability, making it ideal for pilot studies.