Strat-M Membrane Diffusion Correlation to Human Skin

Are you testing active compounds for transdermal diffusion?
Optimizing your formulations? Using enhancers?
Performing safety testing on your formulations?

Strat-M® membrane is predictive of diffusion in human skin for a wide range of compounds and formulations. Use the Compound Correlation Tool to learn how well Strat-M membrane will work for you.


Strat-M® membrane has broad chemical compatibility and is an appropriate test model for compounds across a wide range of physiochemical properties. Seven test compounds ranging in molecular weight from 180 to 392 with log P values (representing relative lipophilicity) of -0.131 to 6.9 were tested for diffusion through human skin and Strat-M membrane. The flux of each compound through human skin and through Strat-M membrane was nearly equivalent, with a mean flux ratio of 1.14.

Strat-M membrane correlation factor compared to human skin
Data points were calculated from the ratios of average values for cumulative flux of seven compounds through Strat-M and human cadaver skin, measured at 8 hours. The solid line represents the ideal 1:1 correlation. More details on the test conditions can be found on the flux charts of the individual compounds.

Diffusion Rate

Whether you are safety testing a slowly diffusing sunscreen active, or optimizing a rapidly diffusing NSAID formulation for pain relief, Strat-M membrane provides the versatility to generate meaningful data.

Strat-M membrane diffusion rate compared to human skin
Transdermal diffusion testing was conducted for several formulations with varying diffusion rates to assess correlation between Strat-M membrane and human cadaver skin. Six Franz cells were used for each formulation—three with Strat-M membrane and three with human cadaver skin. The donor chambers were loaded with 500 ┬ÁL of the formulations. Samples were collected hourly and analyzed by HPLC. The results showed correlation between human skin and Strat-M membrane over a range of diffusion rates.

Sensitive to Enhancers

Strat-M membrane exhibits differential permeability in the presence of enhancers, so it is appropriate for use during formulation optimization.

Strat-M membrane cumulative flux compared to human skin
Caffeine Solution in Propylene Glycol & Propylene Glycol + Oleic Acid showing similar diffusion behavior between human skin and Strat-M membrane as a permeation enhancer (Oleic acid) is added to the formulation.

Note: Information presented is based on preliminary development tests. Official claims will be based on product validation results.