Table 1.

Membranes used in diffusion studies as a surrogate of excised skins [9].

Membranes	Materials	Pros	Cons
Silicon based	Silastic, Polydimethylsiloxane (PDMS), Silatos	Cost effective, good storage conditions, good reproducibility, low variability	Fails to incorporate components like metabolism, distribution, and excretion
Cellulose-based	Pure cellulose, Cellulose-acetate, cellulose nitrate (glycerin and preservatives can be added for better flexibility)	Cost effective, good storage conditions, good reproducibility, low variability, very low protein binding capacity, hydrophilic, improved solvent resistance	Fails to incorporate components like metabolism, distribution, and excretion, lubrication is needed, not lipophilic
Synthetic polymer based	Nylon (aliphatic polyamides) (hydrophobic), polysulfone, polycarbonates (high flux membranes)	Low protein binding, chemical inertness, cost-effective, lack of tortuosity of the pores, good chemical stability	Higher cost, lower availability, fails to incorporate components like metabolism, distribution, and excretion
Strat-M®	Multilayer polyester sulfone polyolefin	Multiple layers with different permeability good storage conditions good reproducibility low variability, good correlation with excised skin	Fails to incorporate components like metabolism, distribution, and excretion
Chitosan	Chitosan-alginate Poloxamer 188	Porosity can be varied based on molecular weight and origin (fungal or animal) good physicochemical properties, thickness, roughness, opacity, liquid uptake, and water vapor permeability can be modified, non-toxic	Fails to incorporate components like metabolism, distribution, and excretion